OmniGears: added missing persistent=false

settings that are stored in Settings dont need to
be made persistent again in the settings storage
and should use android:persistent=false

This will also make it possible to change
the type of a settings without interference
with the settings storage breaking upgrades

Change-Id: I3af444abd43fbac7465e6fa6c033de3da7a09daa

Conflicts:
	res/xml/bars_settings.xml
	res/xml/brightness_settings.xml
	res/xml/button_settings.xml
	res/xml/menus_settings.xml
	res/xml/more_interface_settings.xml