* fix(large-video): ensure switch to local video when all others leave
This handles the case where User A and B are in a call and B has
no audio or video. Then B leaves. User A would see User B left
on large video. Instead, User A should see self view on large.
* squash: always update large video if it is empty
* squash: add largeVideo check for filmstrip only mode
d1ea29beeb