For key frames: increase the sequence index until the last 7 bits are
all zeroes. If this results in an overflow, wraparound to 0.
Also:
* Allow setting and getting the sequence index
* Allow getting LayerId
Bug: webrtc:358039777
Change-Id: Ibe16689a3d1eb5706d4fce5c9220770046f26896
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/362540
Reviewed-by: Erik Språng <sprang@webrtc.org>
Auto-Submit: Fanny Linderborg <linderborg@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#43042}