Support subtitle in .mkv files

[MajidArabi]

Hi. To display embedded soft subtitles in .mkv files using ExoPlayer, we need to set

subtitleView?.visibility = View.VISIBLE

to ensure the subtitles are rendered.
Could you provide an implementation for this?

[kdroidFilter]

yes indeed my subtitle implementation does not (yet) support subtitles in .mkv, as it is a multiplatform library, I need to support this on all platforms, so I can't just use exo player. I have to modify the existing implementation to support .mkv