[android] fix map in dialog activity

platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/maplayout/MapInDialogActivity.java

@@ -1,6 +1,8 @@
 package com.mapbox.mapboxsdk.testapp.activity.maplayout;
 
+import android.app.Dialog;
 import android.os.Bundle;
+import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v4.app.DialogFragment;
 import android.support.v4.app.FragmentManager;
@@ -65,6 +67,22 @@ public class MapInDialogActivity extends AppCompatActivity {
       mapView.onCreate(savedInstanceState);
     }
 
+    @NonNull
+    @Override
+    public Dialog onCreateDialog(Bundle savedInstanceState) {
+      return new Dialog(getActivity(), getTheme()) {
+        boolean destroyed = false;
+        @Override
+        public void dismiss() {
+          if (mapView != null && !destroyed) {
+            mapView.onDestroy();
+            destroyed = true;
+          }
+          super.dismiss();
+        }
+      };
+    }
+
     @Override
     public void onStart() {
       super.onStart();
@@ -89,12 +107,6 @@ public class MapInDialogActivity extends AppCompatActivity {
       mapView.onStop();
     }
 
-    @Override
-    public void onDestroy() {
-      super.onDestroy();
-      mapView.onDestroy();
-    }
-
     @Override
     public void onLowMemory() {
       super.onLowMemory();