Observe location changes

Register a location change broadcast receiver, and allow liveDatas to
observe it. Also ensured that providers with background permissions do
not set their state to the background permission, without first checking
the provider state.

Fixes: 156793511
Test: Go to the PermissionApps Screen for location, or to the
permissions screen for Google Play Services, and enable or disable
location using the upper tray.

Change-Id: Iddbc025b095f723cbd6c9b5da78fbb851b3dfb59