This is a cleanup of simulcast.cc. bitrate_priority is not needed to decide simulcast config. Move setting of bitrate priority in VideoStream one level up, to EncoderStreamFactory::CreateEncoderStreams(). Bug: webrtc:351644568 Change-Id: I002d728ccf8d141fe4bbb32b390129ce57c830cd Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/357101 Commit-Queue: Sergey Silkin <ssilkin@webrtc.org> Reviewed-by: Erik Språng <sprang@webrtc.org> Cr-Commit-Position: refs/heads/main@{#42629}