Update to ExoPlayer 2.13.2

[Redirion]

What is it?

• Bugfix (user facing)
• Feature (user facing)
• Codebase improvement (dev facing)
• Meta improvement to the project (dev facing)

Description of the changes in your PR

Updates ExoPlayer and fixes related deprecations where applicable.

@TacoTheDank I have also changed the setPlayWhenReady calls to play() and pause() where appropriate

APK testing

the APK can be found by going to the "Checks" tab below the title and then on "artifacts" on the right.

Due diligence

• I read the contribution guidelines.

[Redirion]

I have tested on my Pixel 4a (Android 11): basic video playback, play, pause and subtitles tested. Works so far, so any more feedback is appreciated.

[TacoTheDank]

Overall very nice at a quick glance. Also, thanks for this; I was having trouble figuring out how to update ExoPlayer to 2.13 in another repository, so this will help a ton!

(You can ignore this little nitpick of mine, since it's not important at all, but I feel that the changes concerning the ExoPlayer 2.13.x upgrade should be a separate commit from the changes that concern previous ExoPlayer updates (the MediaItem builders, setPlayWhenReady, setMediaSource, etc.)

[Stypox]

Looks good at a firsf glance, thank you!

[Stypox]

I tested a little bit: functionality-wise everything works fine, but the play-pause buttons always show the "Pause" icon even when the video is paused @Redirion

[Redirion]

I have restored the "onPlayerStateChanged" listener. The splitting up into "onPlaybackStateChanged" and "onPlayWhenReadyChanged" was causing the issues. This further simplifies this PR and makes it easy to merge in my opinion.

[Stypox]

I tested, everything works fine. Thanks :-)