By initialization, time since backoff is unlimited at startup. Bug: none Change-Id: I9693cd09b7201606374a8bf9a0a03e6ee83191d3 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/232611 Commit-Queue: Fanny Linderborg <linderborg@webrtc.org> Reviewed-by: Fanny Linderborg <linderborg@webrtc.org> Cr-Commit-Position: refs/heads/main@{#35076}