[Settings] Support getSystemService(Class<T>)

Add getSystemService(Class<T>) to align the capability with framework
part.

This is a back port from aosp/1639943, aosp/1645152 and aosp/1648047

Bug: 179640862
Test: local
Change-Id: I035db55a71f94000ca35f8d71f03c19208423c73

src/com/android/settings/wifi/WifiWakeupPreferenceController.java

@@ -73,7 +73,7 @@ public class WifiWakeupPreferenceController extends TogglePreferenceController i
 
     public WifiWakeupPreferenceController(Context context) {
         super(context, KEY_ENABLE_WIFI_WAKEUP);
-        mLocationManager = (LocationManager) context.getSystemService(Service.LOCATION_SERVICE);
+        mLocationManager = context.getSystemService(LocationManager.class);
         mWifiManager = context.getSystemService(WifiManager.class);
     }