This cl add a configuration flag to allow REMB messages to be sent immediately when the bitrate value have changed. The remb message is still included in all following compound packets. Bug: None Change-Id: I9f71d30cddbccd095e1d2971247c731bd1727d32 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/169221 Commit-Queue: Per Kjellander <perkj@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Cr-Commit-Position: refs/heads/master@{#30627}