To make it usable in tests without depending on all of CallTest. Bug: None Change-Id: Ie3102ab71bcfe3862dd6c35d3285098e961e54df Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/262807 Reviewed-by: Tomas Gunnarsson <tommi@webrtc.org> Commit-Queue: Niels Moller <nisse@webrtc.org> Cr-Commit-Position: refs/heads/main@{#36932}