private void onHostPause() {
        if (mViewAdded && mGLInitialized && mSelectedSceneIndex < mSceneArray.size()) {
            VRTScene childScene = mSceneArray.get(mSelectedSceneIndex);
            childScene.onHostPause();
        }

        if (mViroView != null){
            mViroView.onActivityPaused(mReactContext.getCurrentActivity());
        }
    }
If we're exiting Viro and destroying the renderer, notify the MaterialManager so that if
the application doesn't get killed, then the next time Viro starts, we know to reload the
materials.
android/viro_bridge/src/main/java/com/viromedia/bridge/component/VRT3DSceneNavigator.java