HD control is hidden initially. On first play of video, when
player.getAvailableQualityLevels returns a non-empty array, it will eventually display, if HD qualities are available (highres, hd1080, hd720). [BLD-937]
Merge pull request #3151 from edx/jmclaus/disable_hd_control_when_hd_qualities_not_available

Disable HD control when HD is not available [BLD-937]