SysUI: Don't recreate controllers.

The various controllers, such as mLocationController, get recreated
every time the status bar is recreated due to a theme change.  We
should only need to create these if they are null, otherwise use
the controller as is.  Also, each of these controlers registers
themselves as a broadcast receiver and are never unregistered before
recreating them.

Change-Id: I6215aae5a82b7ced8f0f25cf592a804d38825260
Merge "SysUI: Don't recreate controllers." into cm-11.0
Merge pull request #2 from CyanogenMod/cm-11.0

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