Do not disable controls on startup
Do not disable controls on startup

Disabling the controls on startup made more sense back when this demo
would always have a video element showing.  Now that the video element
is first shown when a video is played, having controls initially
disabled created some unintended side-effects:

1. Reload the page with an asset selected, and no buffering spinner is
   displayed
2. Reload the page with a failing asset selected, and there will be no
   way to close the video

Change-Id: I7b2054cf524c0e2091ec02a5df4ec2422cb5675f

shaka-project/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,tvoli/shaka-player,shaka-project/shaka-player,tvoli/shaka-player,tvoli/shaka-player,shaka-project/shaka-player