[1/2] Settings: Add percent only and none options for battery icon

PS3: Add an option for percent next to battery bar
Also changed implementation to use a textview as this is much cleaner
Implemented percent color chage on critical and low battery levels.

PS4: clean up unused "submenu" items, reword string, move array around.

PS5: reword to "Battery bar & percent left"

Change-Id: I6176e29857eaecd616ca8210ce06510467dc2921

Conflicts:
	res/values/custom_strings.xml
	src/com/android/settings/fuelgauge/PowerUsageSummary.java