@Override
        public void onHostResume() {
            VRT3DSceneNavigator navigator = mNavigator.get();
            if (navigator == null) {
                return;
            }
            navigator.onHostResume();
        }
VRT3DSceneNavigator manages the various scenes{@link ViroViewScene} that a Viro App can navigate between.
android/viro_bridge/src/main/java/com/viromedia/bridge/component/VRT3DSceneNavigator.java