VID-1515 Launch agegate when player is loaded

This is code from Ooyala. To fix the issue with iPhone's sometimes not
closing the video player which leaves the agegate stranded in the
background. Instead, we launch the agegate as soon as the player is
ready, rather than waiting for the user to click the thumbnail. Note,
preloading the agegate like this only occurs on mobile.
Merge pull request #3409 from Wikia/VID-1515

VID-1515 Launch agegate when player is loaded