Feature/june changes (#525)
* Fixed cache clear on Android
* Added file check for file data source.
* Fix for black screen issue on iOS
* Updated changelog
* fix: iOS crashes encountered mainly when playing lots of video in HLS format. I definitely encounter a crash line 380 (#513)
* Updated changelog
* Added key parameter in BetterPlayerCacheConfiguration to provide way to re-use same video between app session
* Format, updated pubspec.yaml
Co-authored-by: themadmrj <themadmrj@users.noreply.github.com>
Co-authored-by: Alexandre Roux <alex@tekartik.com>
