Update changelog for v2.1.4
Update changelog for v2.1.4

Change-Id: Iced9e48ea21f0b7c067e796dc090710bdd00a7b6

shaka-project/shaka-player,TheModMaker/shaka-player,TheModMaker/shaka-player,tvoli/shaka-player,TheModMaker/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,TheModMaker/shaka-player,shaka-project/shaka-player,vimond/shaka-player,tvoli/shaka-player,vimond/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,vimond/shaka-player