Amend release notes for 2.6.0 release
Amend release notes for 2.6.0 release

MaTriXy/ExoPlayer,superbderrick/ExoPlayer,kiall/ExoPlayer,kiall/ExoPlayer,ened/ExoPlayer,tntcrowd/ExoPlayer,superbderrick/ExoPlayer,ebr11/ExoPlayer,tntcrowd/ExoPlayer,tntcrowd/ExoPlayer,saki4510t/ExoPlayer,amzn/exoplayer-amazon-port,amzn/exoplayer-amazon-port,superbderrick/ExoPlayer,androidx/media,ened/ExoPlayer,google/ExoPlayer,saki4510t/ExoPlayer,saki4510t/ExoPlayer,stari4ek/ExoPlayer,ebr11/ExoPlayer,google/ExoPlayer,kiall/ExoPlayer,MaTriXy/ExoPlayer,stari4ek/ExoPlayer,google/ExoPlayer,ened/ExoPlayer,MaTriXy/ExoPlayer,ebr11/ExoPlayer,stari4ek/ExoPlayer,amzn/exoplayer-amazon-port,androidx/media,androidx/media