And fix tests that still depend on extensions to be known by the receiver. Change-Id: I62227829af81af07769189e547f1cdb8ed4d06b3 Bug: webrtc:7135,webrtc:14795 Change-Id: I62227829af81af07769189e547f1cdb8ed4d06b3 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/290996 Commit-Queue: Per Kjellander <perkj@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Reviewed-by: Erik Språng <sprang@webrtc.org> Cr-Commit-Position: refs/heads/main@{#39184}