Fix: Clear static impl reference on service destroy

Author: SBALAVIGNESH123

play-services-wearable/core/src/main/java/org/microg/gms/wearable/WearableService.java

@@ -48,6 +48,7 @@ public void onCreate() {
     public void onDestroy() {
         super.onDestroy();
         wearable.stop();
+        impl = null;
     }
 
     @Override