This completes the conversion of ByteBufferReader and ByteBufferWriter to uint8_t. No-Try: True Bug: webrtc:15661 Change-Id: I4152a8a4fd2462282d4107b3c2eed19acc8b29b0 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/331640 Commit-Queue: Harald Alvestrand <hta@webrtc.org> Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org> Cr-Commit-Position: refs/heads/main@{#41403}