SystemUI: respect statusbar background for themes

one love

Change-Id: Iaa71bdec2b258b13b581cacb618be2a90eba3020
Signed-off-by: Roman Birg <romanbirg@gmail.com>
Signed-off-by: PipelinerArd <kristoferard@gmail.com>

Conflicts:
	packages/SystemUI/res/layout/status_bar.xml