ClearTo logic relies on clear to sequence number follows first_seq_num_ Bug: chromium:370689424 Change-Id: I12874d5ce7adfdcf9c0691acacdd2b8ae41ce307 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/371320 Commit-Queue: Danil Chapovalov <danilchap@webrtc.org> Reviewed-by: Rasmus Brandt <brandtr@webrtc.org> Cr-Commit-Position: refs/heads/main@{#43558}