GitLab

When the owner of the device is a supervised user, then remove
the 'Add Users' button in users_page.

Bug: 945082
Change-Id: Ib3acc6aaa955165471ca1faa36186bf3efe1dd49
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1722986Reviewed-by: Michael Giuffrida <michaelpg@chromium.org>
Commit-Queue: Yilkal Abe <yilkal@chromium.org>
Cr-Commit-Position: refs/heads/master@{#682063}