Also update the tests that depend on FakeMediaEngine.
Bug: webrtc:13931
Change-Id: Ia608c4ce68a29e45174b68ba0103af31e9a7d3d1
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/294280
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Commit-Queue: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39345}