BatteryService: add option to disable charging indicatior led

Change-Id: I9e0f770f3fa3117c8e45ab5c2f3eef5384649105
Signed-off-by: Dirk Rettschlag <dirk.rettschlag@gmail.com>
Merge pull request #8 from AOKP/kitkat

BatteryService: add option to disable charging indicatior led