Mux Data SDK for ExoPlayer v3.0.0

We are announcing the exciting and extensive release of the Mux Data SDK v3.0.0 for ExoPlayer. This update converts most of the SDK to Kotlin, removes long-deprecated methods, and adds API changes. A more simple SDK setup process no longer requires you to specify the screen size of your device. You may now pass your `ENV_KEY` through a constructor instead of supplying it to `CustomerPlayerData`. Finally, we removed exposed internal callback methods that likely will not impact you.

For the full list of API changes, check out the release notes on GitHub.