PowerManager: Don't wake up device when charger is plugged/unplugged (2/2)

This will add the option to disable waking up the device when a charger
is plugged or unplugged.

PS2: hide option if device is already set to never wake up
PS7: Fixed whitespaces, and conflicts
PS14: missing semilcolon? L2COMPILE AMFG

Change-Id: I885b01aca0501e9d3b7d3b34a3b7a553f1e086fb