Add _usec suffix to trial_verification_time field in cert_logger.proto

Bug: 1008994
Change-Id: I10a52af910605852786ffcf888276764d6660c39
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1835158
Reviewed-by: Emily Stark <estark@chromium.org>
Commit-Queue: Matt Mueller <mattm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702208}
3 files changed