fix top buttons not clickable while video is loading

[fowwest]

There's a bug with top buttons with current version, that is, when video loading view is shown, top buttons like back button is not pressable.
I debugged the cause of the issue and found that it's because loading view is rendered over top buttons covering the entire screen with absolute position.
So i fixed it by switching those two lines as follows:

Before:

{ this.renderTopControls() }
{ this.renderLoader() }

After:

{ this.renderLoader() }
{ this.renderTopControls() }

[kylemilloy]

This has conflicts with the branch now but I've added your changes to 2.5.1. Thanks!