[Android] Update Exoplayer to 2.8.X

[Chubacca]

Can we update Exoplayer to use 2.8.X? We currently have a hybrid native/react-native app and would like to use the newest Exoplayer, and the current react-native-video code is not compatible with 2.8.X.

Specifically 2.8.X removed the method "clearSelectionOverrides" in this commit. However, react-native-video calls the method here. There will potentially be other incompatibilities, but this was the exception we ran into first.

Platform

Which player are you experiencing the problem on:

• Android ExoPlayer

[cobarx]

I'll do this pretty soon and handle the API changes. There were some outstanding PRs I wanted to get merged first to avoid conflicts, but I think those are in now.

[cobarx]

Done in #1170. I've handled all text track stuff. I didn't hit any issues with other features not working post upgrade, but testing would be welcome in advance of the release. You can grab the update off the master branch.

[Chubacca]

Did some minor testing off master and everything looks fine!