Remove default implementation of PeerConnectionInterface::SetBitrate.

This was included to avoid breaking chromium, which now includes its own implementation (https://chromium.googlesource.com/chromium/src/+/725cb26dab3bae1cbb3339ed13186848f608cfad).

BUG=webrtc:7395

Review-Url: https://codereview.webrtc.org/2924243003
Cr-Original-Commit-Position: refs/heads/master@{#19063}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 83dc6b6f5380d7c03f5ebfe2553bf4a3147e2d1c
1 file changed