Status bar brightness control

+ added some fixes to original implementation (thanks mostly cm for that)
+ add multiuser support

Change-Id: Ibc5cc15a9b43eade73670d308d5cc788c93b6210
fb: add DeviceUtils helper class

for common calls we need later on several places

initial push with only display type support

Change-Id: Ic8856512d8a7540eda3e4ba8d28f3eec3e6961d0
Merge remote-tracking branch 'upstream/kk4.4' into kk4.4