Revert "[Settings] Support getSystemService(Class<T>)"

This reverts commit d5ccde31a8.

Reason for revert: failure on test cases

Change-Id: I0a179a6ebb5ef1dec566ce6e8facd5f3b82d7c8a

src/com/android/settings/wifi/p2p/WifiP2pPreferenceController.java

@@ -71,7 +71,7 @@ public class WifiP2pPreferenceController extends AbstractPreferenceController
         super(context);
         mWifiManager = wifiManager;
         lifecycle.addObserver(this);
-        mLocationManager = context.getSystemService(LocationManager.class);
+        mLocationManager = (LocationManager) context.getSystemService(Service.LOCATION_SERVICE);
     }
 
     @Override