Disable screen dimming when charging (1/2)

new setting to disable screen dimming if stay awake is enabled

Change-Id: I65b845bf98420445f51e3740a6c1b6fd39e592ef

Conflicts:
	services/java/com/android/server/power/PowerManagerService.java
Wakelock blocker: initial (1/2)

port 2gtoggle as well.