Use speech content instead of white noise and enable target vs measured
bitrate tests.
Bug: webrtc:11360
Change-Id: If8c8e73f943eda14efeb22ba406c7a1bed7d32b4
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/168660
Commit-Queue: Alessio Bazzica <alessiob@webrtc.org>
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#30630}
