The voice engine expects send bitrates no more than the maximum for the codec. For example, 510kbps for opus. So if "b=AS" sets a maximum above the codec maximum, WebRtcVoiceEngine needs to cap it. BUG=603690 Review-Url: https://codereview.webrtc.org/1920123002 Cr-Commit-Position: refs/heads/master@{#12537}