paycheck: refined default metadata signature logic

We now only discover and use a default metadata signature when check is
actually triggered and a public key provided; otherwise, we could be
forcing the check to fail. This also avoids unnecessary output and
directs informational output to stderr.

TEST=Unit/integration tests pass

Change-Id: I39df4060afd12a5d54869a6803141bc3e0d2f89b
Reviewed-by: Gilad Arnold <>
Tested-by: Gilad Arnold <>
Commit-Queue: David James <>
1 file changed