MIssingGlContextApplication Exception while getting RGB and Depth Image from ARcore session

I want to capture the RGB image and Depth map of the same frame and store it as a bitmap. As I'm new to ARCore, I tried modifying the sample of Hello AR provided by Google in the below link.

https://developers.google.com/ar/develop/unity/tutorials/hello-ar-sample

In the main layout I created a button, and assigned the onClick() function as captureFrame() defined as below.

I was planning to create the bitmap from the plane data from the RGBImage and DepthImage objects.

public void captureFrame(View view){
    Toast.makeText(getApplicationContext(),"Capturing depth and rgb photo",Toast.LENGTH_SHORT).show();


    if (session == null) {
      return;
    }
    // Notify ARCore session that the view size changed so that the perspective matrix and
    // the video background can be properly adjusted.
    displayRotationHelper.updateSessionIfNeeded(session);

    try {
      session.setCameraTextureName(backgroundRenderer.getTextureId());

      Frame frame = session.update();
      Image RGBImage = frame.acquireCameraImage();
      Image DepthImage = frame.acquireDepthImage();

      Log.d("Amey","Format of the RGB Image: " + RGBImage.getFormat());
      Log.d("Amey","Format of the Depth Image: " + DepthImage.getFormat());

    } catch (Exception e) {
      e.printStackTrace();
    }

  }

Though, I'm getting the following error from session.update():

W/System.err: com.google.ar.core.exceptions.MissingGlContextException

Can anyone suggest a workaround for this problem, or any better approach for getting bitmaps of RGB and depth images through ARcore?