Reduce observers in SystemUI: KeyButtonView

This is based on the work by Jens Doll for the StatusBarIconView

The ContentObserver class will be a singleton, so there is only
one observer for all buttons.

On my Nexus 10 it reduced the observer count from 48 to 4.

This version fixes the funky glow effect.

Change-Id: Ie242e3771c41f6010ac12246372107a2a3e165cd
Signed-off-by: Dirk Rettschlag <dirk.rettschlag@gmail.com>
Fix BatteryBar showing on all 3 locations

Change-Id: Idbdd16ea5442b032119ce48d586b2207e8cf0281
Signed-off-by: Dirk Rettschlag <dirk.rettschlag@gmail.com>
Telephony: Add DCHSPAP to getTcpBufferSizesPropName

Change-Id: I868f0eae2db6032b43e9c1a1bd23860ab7bbebca
Merge "Telephony: Add DCHSPAP to getTcpBufferSizesPropName" into jb-mr1
Merge "Reduce observers in SystemUI: KeyButtonView" into jb-mr1
Merge "Fix BatteryBar showing on all 3 locations" into jb-mr1
Merge remote-tracking branch 'aokp/jb-mr1' into jb-mr1