QuickSettings : Add BatterySaver Tile (1/2)

PS1: Minor changes

Signed-off-by: hany <hany.alsamman@gmail.com>

Conflicts:
	core/java/com/android/internal/util/cm/QSConstants.java
	packages/SystemUI/res/values/probam_strings.xml
	packages/SystemUI/src/com/android/systemui/statusbar/phone/QuickSettingsController.java