Also parameterizes the PeerConnection RTP unit tests to test
Unified Plan also.
Bug: webrtc:8587
Change-Id: I7661d9f2ec4b3bce0d2e2979035fa02225e3f118
Reviewed-on: https://webrtc-review.googlesource.com/73284
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Reviewed-by: Seth Hampson <shampson@webrtc.org>
Commit-Queue: Steve Anton <steveanton@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23157}