This is a reland of commit 02b5f3c9c12cddf3fc6e9125238b77ddb44f3b53
without making SetRemoteFingerprint private (but adding a deprecation warning)
Original change's description:
> dtls: allow dtls role to change during DTLS restart
>
> which is characterized by a change in remote fingerprint and
> causes a new DTLS handshake. This allows renegotiating the
> client/server role as well.
> Spec guidance is provided by
> https://www.rfc-editor.org/rfc/rfc5763#section-6.6
>
> BUG=webrtc:5768
>
> Change-Id: I0e8630c0c5907cc92720762a4320ad21a6190d28
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/271680
> Reviewed-by: Harald Alvestrand <hta@webrtc.org>
> Commit-Queue: Philipp Hancke <phancke@microsoft.com>
> Cr-Commit-Position: refs/heads/main@{#37821}
Bug: webrtc:5768
Change-Id: I8dd674db8b683160013e1b4aa7776775d130978f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/272221
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Philipp Hancke <phancke@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#37838}
4a3b5ccfd5