Added error checking in AudioIngress and AudioEgress to detect situations where codecs have not been set; added additional unit tests for VoipCore Bug: webrtc:11251 Change-Id: Ibd57e518892c76e2865b844ba866e380a565dd6b Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/180229 Commit-Queue: Tim Na <natim@webrtc.org> Reviewed-by: Per Åhgren <peah@webrtc.org> Reviewed-by: Tim Na <natim@webrtc.org> Cr-Commit-Position: refs/heads/master@{#31874}