GitLab

Now we are using AttestationClient directly instead of passing through
CryptohomeClient.

BUG=b:158955123
TEST=build ok.

Change-Id: Ib5ee5262e8dc6bc759dad9eb7737a04e89a0de3e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2505263
Commit-Queue: Leo Lai <cylai@google.com>
Reviewed-by: Maksim Ivanov <emaxx@chromium.org>
Cr-Commit-Position: refs/heads/master@{#823445}