Update Remoting to new CreateSessionDescription signature

Unblocks landing https://webrtc-review.googlesource.com/c/src/+/360020

Bug: webrtc:360909068
Change-Id: I7a2cbd427c3e5d03b8a41a53b8022e32e672eb1b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5826659


Reviewed-by: Joe Downing <joedow@chromium.org>
Commit-Queue: Harald Alvestrand <hta@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1349299}