d4fe3ce902
This extends the RTP header extension API usage to generating answers. Also re-adds unit tests removed by the revert. BUG=chromium:1051821 Change-Id: Ib754284e9a77cb49e22bea7072c475d240f2563b Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/298740 Reviewed-by: Henrik Boström <hbos@webrtc.org> Reviewed-by: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Philipp Hancke <phancke@microsoft.com> Cr-Commit-Position: refs/heads/main@{#39800}