Mark DeviceBlockDevmode support by google_cloud only

Active Directory devices apply the setting that come from device
cloud policy.

BUG=chromium:889893

Change-Id: I0738f35dfdad56042c388699f811b43f3a530501
Reviewed-on: https://chromium-review.googlesource.com/c/1365595
Commit-Queue: Roman Sorokin <rsorokin@chromium.org>
Reviewed-by: Lutz Justen <ljusten@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614681}
1 file changed