Get focal length

[chartungpatmos]

My app needs the camera focal lengths (fx and fy) in pixels for certain calculations. Both ARKit and ARCore expose those values in camera intrinsics:
https://developer.apple.com/documentation/arkit/arcamera/intrinsics
https://developers.google.com/ar/reference/java/com/google/ar/core/CameraIntrinsics
Can you add a function to get those values?