Extends the mocks for rtpreceiver rtpsender and videotrack. This change
allows the external HangoutsKit client to remove its own mocks of rtc
types.
Bug: none
Change-Id: I8ba1752fe7633f9e0bba264a1279f74cc1368a2c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/282900
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Jack Smith <jackdsmith@google.com>
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#38782}
adf35a359e