Use libVLC or libMPV for the android client

[zoriya]

Feature description

Exoplayer (android default's player) can't play all codecs & can't properly display complex subtitles.

Switching to vlc or mpv as a backend would fix this. Both backend options seem to have the same functionalities & advantages from a user's perspective, but the DX changes a lot.

Mpv's api is similar to exoplayer so adapting existing code SHOULD be easy, but no binary release exists.
Vlc does offer a simple release via gradle, but the api is different.

This will be integrated either via contributing it to https://github.com/TheWidlarzGroup/react-native-video or by making our own player package.