the ssrc-group consistency is checked by the media engine. BUG=chromium:1454860 Change-Id: Ib9f60a0e773ffd1810aae4e5f464d12619e94b5c Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/311160 Reviewed-by: Henrik Boström <hbos@webrtc.org> Reviewed-by: Artem Titov <titovartem@webrtc.org> Commit-Queue: Philipp Hancke <phancke@microsoft.com> Cr-Commit-Position: refs/heads/main@{#40389}