GitLab

Make EnterpriseInstallAttributes defer running its
consistency check (which calls cryptohome's TpmIsOwned
method over D-Bus) until the cryptohome service is
available.

Also fix an apparent bug where the check was retried five
times the intended number of times.

BUG=636554

Review-Url: https://codereview.chromium.org/2244443002
Cr-Commit-Position: refs/heads/master@{#419180}