to remove duplicated implementation of these functions between av1 packetizer, av1 depacketizer and video allocation rtp header extension Bug: None Change-Id: I30049f31c289bdb9e0aad6520f5145d1f999e635 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/290731 Commit-Queue: Danil Chapovalov <danilchap@webrtc.org> Reviewed-by: Philip Eliasson <philipel@webrtc.org> Cr-Commit-Position: refs/heads/main@{#39069}