add power menu reboot back

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 Changes to be committed:
	modified:   core/res/res/values/arrays.xml
	modified:   core/res/res/values/strings.xml
	modified:   core/res/res/values/symbols.xml
	modified:   policy/src/com/android/internal/policy/impl/GlobalActions.java
	modified:   services/java/com/android/server/power/ShutdownThread.java