[android] add method addMarkerViews with only one invalidate

* add method addMarkerViews with only one invalidate

* clean sample BulkMarkerActivity

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/maps/MapboxMap.java

@@ -772,7 +772,23 @@ public class MapboxMap {
         mMarkerViewManager.invalidateViewMarkersInVisibleRegion();
         return marker;
     }
-    
+
+    @UiThread
+    @NonNull
+    public List<MarkerView> addMarkerViews(@NonNull List<? extends BaseMarkerViewOptions> markerViewOptions) {
+        List<MarkerView> markers = new ArrayList<>();
+        for (BaseMarkerViewOptions markerViewOption : markerViewOptions) {
+            MarkerView marker = prepareViewMarker(markerViewOption);
+            marker.setMapboxMap(this);
+            long id = mMapView.addMarker(marker);
+            marker.setId(id);
+            mAnnotations.put(id, marker);
+            markers.add(marker);
+        }
+        mMarkerViewManager.invalidateViewMarkersInVisibleRegion();
+        return markers;
+    }
+
     /**
      * <p>
      * Adds multiple markers to this map.

platform/android/MapboxGLAndroidSDKTestApp/src/main/java/com/mapbox/mapboxsdk/testapp/activity/annotation/BulkMarkerActivity.java

@@ -129,15 +129,14 @@ public class BulkMarkerActivity extends AppCompatActivity implements AdapterView
         for (int i = 0; i < amount; i++) {
             randomIndex = random.nextInt(mLocations.size());
             LatLng latLng = mLocations.get(randomIndex);
-            markerOptionsList.add(new MarkerViewOptions()
+            MarkerViewOptions markerOptions = new MarkerViewOptions()
                     .position(latLng)
                     .icon(icon)
                     .title(String.valueOf(i))
-                    .snippet(formatter.format(latLng.getLatitude()) + ", " + formatter.format(latLng.getLongitude())));
-        }
-        for (MarkerViewOptions markerViewOptions : markerOptionsList) {
-            mapboxMap.addMarker(markerViewOptions);
+                    .snippet(formatter.format(latLng.getLatitude()) + ", " + formatter.format(latLng.getLongitude()));
+            markerOptionsList.add(markerOptions);
         }
+        mapboxMap.addMarkerViews(markerOptionsList);
     }
 
     private void showGlMarkers(int amount) {

platform/android/MapboxGLAndroidSDKTestApp/src/main/res/values/strings.xml

@@ -167,6 +167,7 @@
     <string-array name="bulk_marker_list">
         <item>10</item>
         <item>100</item>
+        <item>500</item>
         <item>1000</item>
         <item>10000</item>
     </string-array>