Reason for revert:
Looks like this has caused multiple Android webrtc perf build bot failures in RampUpTest.UpDownUpTransportSequenceNumberRtx
Original issue's description:
> Enable the bayesian bitrate estimator by default.
>
> BUG=webrtc:6566, webrtc:7415
>
> Review-Url: https://codereview.webrtc.org/2749803002
> Cr-Commit-Position: refs/heads/master@{#17475}
> Committed: c53a17f28eTBR=terelius@webrtc.org,magjed@webrtc.org,stefan@webrtc.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=webrtc:6566, webrtc:7415
Review-Url: https://codereview.webrtc.org/2786913003
Cr-Commit-Position: refs/heads/master@{#17476}