"subtitles_location" intent extra is not compatible with Scoped Storage

The "subtitles_location" intent extra (aka PLAY_EXTRA_SUBTITLES_LOCATION) is not compatible with Scoped Storage, since it is a file path and there is no way VLC has permission to read it with Scoped Storage. With Scoped Storage, there is no way for apps to pass data between them through files anymore.

Ideally, "subtitles_location" should accept Uri schemes with various protocols and in particular the content:// protocol. It would then be able to copy the content of Uri to a temp file and pass it to the player core.