Fixes google map null pointer exception (react-native-maps#1403)

AirMapView doDestroy is called before LifecycleEventListener onHostPause. This fixes react-native-maps#1358

Author: chaitanya-bhagavan

lib/android/src/main/java/com/airbnb/android/react/maps/AirMapView.java

@@ -314,7 +314,9 @@ public void onHostPause() {
             map.setMyLocationEnabled(false);
           }
             synchronized (AirMapView.this) {
-                AirMapView.this.onPause();
+                if(!destroyed) {
+                    AirMapView.this.onPause();
+                }
                 paused = true;
             }
         }