Fixes bug where poster and video was displayed simultaneously

Change compileOnly to implementation on gradle (for newer gradle versions and react-native 0.59 support)

Remove video player when entering background correctly

Replace RCTBubblingEventBlock  by RCTDirectEventBlock to avoid event name collision with Expo AV

Adds onPlaybackRateChange info to README

Fix Android audio crash fixes Issue #1417

Why:

* There is a case where groupIndex may be unset

This change addresses the need by:

* Don't chain check for INDEX_UNSET to previous conditional

1319 - fullscreen rotation issues with iOS built-in controls

Fix tvOS picture-in-picture compilation regression.