Update changelog for v2.0.2 release.
Update changelog for v2.0.2 release.

Change-Id: I58c55b2831292956551f13bd0925382c54d4a2ab

TheModMaker/shaka-player,TobbeEdgeware/shaka-player,TheModMaker/shaka-player,vimond/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,brightcove/shaka-player,shaka-project/shaka-player,TheModMaker/shaka-player,tvoli/shaka-player,TobbeEdgeware/shaka-player,tvoli/shaka-player,vimond/shaka-player,indiereign/shaka-player,brightcove/shaka-player,russitto/shaka-player,Ross-cz/shaka-player,shaka-project/shaka-player,shaka-project/shaka-player,brightcove/shaka-player,Ross-cz/shaka-player,vimond/shaka-player,TheModMaker/shaka-player,Ross-cz/shaka-player,indiereign/shaka-player,TobbeEdgeware/shaka-player,indiereign/shaka-player,tvoli/shaka-player,russitto/shaka-player,russitto/shaka-player