Gallery2:Dark UI changes

Gallery2: TRDS goes Slim

Change-Id: I49f42c1b10e654502d46ddb88ac2343efe747a41
Fix activity stack when restarting the screen nail

We were stacking multiple activities, resulting in the need for multiple
destructions (back key events) when killing the camera app

Change-Id: I7ec61c517d25f7e47baf47fcd1696f987631c344