I know that topic is old but here is my DialogButtonMenu.xml. for Silvo skin (Leia)
so c/p it into file, save and restart CE.
U will get “Reboot to Android” in shutdown menu
<?xml version="1.0" encoding="UTF-8"?>
<window>
<defaultcontrol>9000</defaultcontrol>
<include>DialogOpenCloseAnimation</include>
<controls>
<control type="grouplist" id="9000">
<left>705</left>
<width>510</width>
<height>1080</height>
<onleft>9000</onleft>
<onright>9000</onright>
<onup>9000</onup>
<ondown>9000</ondown>
<align>center</align>
<control type="image" id="1">
<width>510</width>
<height>34</height>
<texture border="30,20,30,2">dialog_top2.png</texture>
</control>
<control type="button" id="2">
<description>Exit button</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>Quit()</onclick>
<font>font14</font>
<label>13012</label>
<visible>System.ShowExitButton</visible>
</control>
<control type="button" id="3">
<description>Shutdown button</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>Powerdown()</onclick>
<visible>System.CanPowerDown</visible>
<font>font14</font>
<label>13016</label>
</control>
<control type="button" id="4">
<description>Custom Shutdown Timer</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>AlarmClock(shutdowntimer,Shutdown())</onclick>
<font>font14</font>
<label>20150</label>
<visible>!System.HasAlarm(shutdowntimer)</visible>
<visible>System.CanPowerDown | System.CanSuspend | System.CanHibernate</visible>
</control>
<control type="button" id="5">
<description>Cancel Shutdown Timer</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>CancelAlarm(shutdowntimer)</onclick>
<font>font14</font>
<label>$LOCALIZE[20151]$INFO[System.Alarmpos, (,)]</label>
<visible>System.HasAlarm(shutdowntimer)</visible>
</control>
<control type="button" id="6">
<description>Reboot to Android</description>
<width>510</width>
<height>60</height>
<label>Reboot to Android </label>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>System.ExecWait("/usr/sbin/rebootfromnand")</onclick>
<onclick>Reset()</onclick>
<visible>System.CanReboot</visible>
<font>font14</font>
<label>13013</label>
</control>
<control type="button" id="7">
<description>Hibernate button</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>Hibernate()</onclick>
<visible>System.CanHibernate</visible>
<font>font14</font>
<label>13010</label>
</control>
<control type="button" id="8">
<description>Reboot button</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>Reset()</onclick>
<visible>System.CanReboot</visible>
<font>font14</font>
<label>13013</label>
</control>
<control type="button" id="9">
<description>Logoff button</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>dialog.close(all,true)</onclick>
<onclick>System.LogOff</onclick>
<font>font14</font>
<label>$LOCALIZE[20126] $INFO[system.profilename]</label>
<visible>System.HasLoginScreen | Integer.IsGreater(System.ProfileCount,1)</visible>
<visible>System.Loggedon</visible>
</control>
<control type="togglebutton" id="10">
<description>Master mode button</description>
<width>510</width>
<height>60</height>
<label>20046</label>
<altlabel>20045</altlabel>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<usealttexture>!System.IsMaster</usealttexture>
<alttexturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</alttexturefocus>
<alttexturenofocus border="35,2,35,2">button_shutdown_nofocus.png</alttexturenofocus>
<onclick>xbmc.mastermode</onclick>
<visible>System.HasLocks</visible>
</control>
<control type="button" id="12">
<description>Inhibit idle shutdown</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>InhibitIdleShutdown(true)</onclick>
<font>font14</font>
<label>13017</label>
<visible>System.HasShutdown +!System.IsInhibit</visible>
</control>
<control type="button" id="13">
<description>Allow idle shutdown</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>InhibitIdleShutdown(false)</onclick>
<font>font14</font>
<label>13018</label>
<visible>System.HasShutdown + System.IsInhibit</visible>
</control>
<control type="button" id="14">
<description>Settings</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>Dialog.Close(all,true)</onclick>
<onclick>ActivateWindow(settings)</onclick>
<font>font14</font>
<label>$LOCALIZE[5]</label>
</control>
<control type="button" id="18">
<description>Skin Settings</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>Dialog.Close(all,true)</onclick>
<onclick>ActivateWindow(skinsettings)</onclick>
<font>font14</font>
<label>20077</label>
</control>
<control type="button" id="15">
<description>Favorites</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>ActivateWindow(favourites)</onclick>
<font>font14</font>
<label>1036</label>
</control>
<control type="button" id="17">
<description>Reload Skin button</description>
<width>510</width>
<height>60</height>
<textcolor>grey2</textcolor>
<focusedcolor>white</focusedcolor>
<textwidth>435</textwidth>
<textoffsetx>45</textoffsetx>
<texturefocus colordiffuse="$VAR[HighlightBarColor]" border="35,2,35,2">button_shutdown_focus.png</texturefocus>
<texturenofocus border="35,2,35,2">button_shutdown_nofocus.png</texturenofocus>
<onclick>Dialog.Close(all,true)</onclick>
<onclick>ReloadSkin()</onclick>
<font>font14</font>
<label>20183</label>
</control>
<control type="image" id="16">
<width>510</width>
<height>34</height>
<texture border="30,2,30,20">dialog_bottom2.png</texture>
</control>
</control>
</controls>
</window>