AI 144372: Cleanup Settings support for enabling and disabling location providers:

LocationManagerService now listens for changes to settings,
  making LocationManager.updateProviders() unnecessary.
  Removed LocationManager.updateProviders()
  Added Settings.Secure.setLocationProviderEnabled(), which is a thread-safe way
  of enabling or disabling a single location provider.
  This is safer than reading, modifying and writing the LOCATION_PROVIDERS_ALLOWED directly.
  BUG=1729031

Automated import of CL 144372

location/java/android/location/LocationManager.java

@@ -312,20 +312,6 @@ public class LocationManager {
         return goodProviders;
     }
 
-    /**
-     * Propagates the enabled/disabled state of the providers from the system
-     * settings to the providers themselves.
-     *
-     * {@hide}
-     */
-    public void updateProviders() {
-        try {
-            mService.updateProviders();
-        } catch (RemoteException ex) {
-            Log.e(TAG, "updateProviders: RemoteException", ex);
-        }
-    }
-
     /**
      * Returns the next looser power requirement, in the sequence:
      *