battery saver mode: updates (1/2)

credits to Yanuar Harry<ai.the.smarties.physics@gmail.com>

Change-Id: I5516e6293b052dc8da17f3ad30e848200ea3e6f5
Signed-off-by: Dan Trifan <jimsth@gmail.com>

Conflicts:

	packages/SystemUI/AndroidManifest.xml
	packages/SystemUI/res/values/vanir_strings.xml