[Unity] App crashing and laggy tracking on Focus 3 using VideoPlayer

[Alex_HTC]

@vrunchForgive the delay - one thing to try here is to use AVPro, as there seems to be some memory leak in the unity video player with looping stereo video in vr (which does not happen in non-vr mode, say if you built it as a non-vr app and launched it on the same headset)