remove
Removes the existing SubtitleTrack with trackId from the list of available subtitle tracks. If the track is currently selected, it will be de-selected and then removed. If no SubtitleTrack with the given trackId exists, the call has no effect. Use setSubtitleTrack and pass null as the trackId to just disable but not remove an active SubtitleTrack.
Has no effect if the source is not attached to a player.
Limitations
This function is not supported while casting to a cast-compatible device.