[AF] Fix flakiness in integration tests for server address metadata sync

This is a speculative fix of rare flakiness. Before this CL, in rare
cases, each client would have a different fake time value. Combined with
another rare race condition in converting server addresses to local
addresses, it would result in initial sync never converging.

Bug: 911953
Change-Id: Ic628cac80b0ffd8977bb29fa5948109366801803
Reviewed-on: https://chromium-review.googlesource.com/c/1373843
Commit-Queue: Sebastien Seguin-Gagnon <sebsg@chromium.org>
Reviewed-by: Sebastien Seguin-Gagnon <sebsg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615939}
1 file changed