Applies an rule-of-thirds grid overlay to the self-preview
Applies an rule-of-thirds grid overlay to the self-preview video window. This is useful for passively nudging guests to better center themselves while on camera.
Please note: As of v19.0, this only works for guests of a room or of a faux-room. It doesn't yet support basic push/view links, as those don't use the auto-mixer code -- which is where this code is currently applied.