title: MapWidget crash issue while using on Fragment
body: <p>I am trying to use DJI UX SDK Map-widget in Android Fragment. Its working fine with activity but when i use that widget with fragment its not working.</p>
  
  <p>Does anyone know what the problem could be?</p>
  
  <p>Here is the code that i have implemented.</p>
  
  <pre><code>public class HomeFragment extends Fragment{
      private MapWidget mapWidget;
  
      public HomeFragment() {
      }
  
      @Nullable
      @Override
      public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
          View inflate = inflater.inflate(R.layout.fragment_home, container, false);
          mapWidget = inflate.findViewById(R.id.map_widget);
          mapWidget = inflate.findViewById(R.id.map_widget);
          mapWidget.initGoogleMap(new MapWidget.OnMapReadyListener() {
              @Override
              public void onMapReady(@NonNull DJIMap djiMap) {
              }
          });
          return inflate;
      }
  
      @Override
      public void onResume() {
          super.onResume();
          mapWidget.onResume();
      }
  
      @Override
      public void onPause() {
          super.onPause();
          mapWidget.onPause();
      }
  
      @Override
      public void onDestroy() {
          super.onDestroy();
          mapWidget.onDestroy();
      }
  
      @Override
      public void onLowMemory() {
          super.onLowMemory();
          mapWidget.onLowMemory();
      }
  }
  </code></pre>
  
  <p><strong>StackTrace</strong></p>
  
  <blockquote>
    <p>Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'void com.google.maps.api.android.lib6.impl.bo.o()' on a null object reference
            at com.google.maps.api.android.lib6.impl.cw.b(:com.google.android.gms.dynamite_mapsdynamite@12874021@12.8.74 (040306-204998136):21)
            at com.google.android.gms.maps.internal.w.a(:com.google.android.gms.dynamite_mapsdynamite@12874021@12.8.74 (040306-204998136):12)
            at fc.onTransact(:com.google.android.gms.dynamite_mapsdynamite@12874021@12.8.74 (040306-204998136):12)
            at android.os.Binder.transact(Binder.java:387)
            at com.google.android.gms.internal.zzeu.zzb(Unknown Source)
            at com.google.android.gms.maps.internal.zzk.onResume(Unknown Source)
            at com.google.android.gms.maps.MapView$zza.onResume(Unknown Source)
            at com.google.android.gms.dynamic.zzh.zzb(Unknown Source)
            at com.google.android.gms.dynamic.zzb.zza(Unknown Source)
            at com.google.android.gms.maps.MapView$zzb.zza(Unknown Source)
            at com.google.android.gms.dynamic.zza.zza(Unknown Source)
            at com.google.android.gms.dynamic.zza.onResume(Unknown Source)
            at com.google.android.gms.maps.MapView.onResume(Unknown Source)
            at dji.ux.widget.MapWidget.onResume(Unknown Source)
            at com.xxx.xxx.HomeFragment.onResume(HomeFragment.java)</p>
  </blockquote>