x265/HLS support in media browser

[prairiesnpr]

Currently the android app supports playing x265 video through exoplayer which works well for viewing streams. This functionality is not present in the media browser when viewing x265 clips. It would be great if we could add this, would really make home assistant a one stop app if you have x265 security cameras.

I did try to solve this, but am clearly not a front end developer.

I naively thought that we could add "allowExoPlayer" here https://github.com/home-assistant/frontend/blob/dev/src/panels/media-browser/hui-dialog-web-browser-play-media.ts#L80 similar to https://github.com/home-assistant/frontend/blob/dev/src/dialogs/more-info/controls/more-info-camera.ts#L53

But this didn't work for me, all the x265 samples I tried matched the mime type of "video/mp4" not "application/x-mpegURL" and thus it didn't attempt to use the ha-hls-player.

Anyone have suggestions on how this could be implemented?