This allows us to update downstreams to no longer use the constructor
that includes groupid. This is part of a small cleanup of StreamParams.
Bug: webrtc:9042
Change-Id: I0343fd9213157614023e5990f6e776b4f56de144
Reviewed-on: https://webrtc-review.googlesource.com/63421
Commit-Queue: Seth Hampson <shampson@webrtc.org>
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22695}