Fallback to squared pixel generator if no camera exist.
Remove render scaling and rendering of local preview since contains
bugs that crash the demo. Use rtc::Buffer for storing the rendered
frames.
Run build cleaner
Bug: none
Change-Id: I46dc972eaa50069433d8afaa1fe38380edd3d337
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/367120
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Per Kjellander <perkj@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#43350}
060ae594b3