SystemUI : Port forward statusbar brightness control

Brings back the status bar brightness control from cm-10.2/cm-11

Change-Id: Icc04e7da3286e9925f8b90528c1e022b33d33e9d
Signed-off-by: Chet Kener <Cl3Kener@gmail.com>

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/phone/PhoneStatusBar.java

Signed-off-by: Chet Kener <Cl3Kener@gmail.com>