Allowlist gcertstatus command to be run

With https://team-review.git.corp.google.com/c/foundry-x/re-client/+/2045536, reclient is starting to use gcertstatus instead of prodcertstatus to check for validity of google prod creds.

I'll remove the allowlist for prodcertstatus in a subsequent CL after new reclient is released.

Bug: b/169675226
Change-Id: I0e760c863d534b7a5744daf5f89f530be3d296ff