GitLab

Update the policy documentation and the pref's default value
accordingly.

BUG=511300

Change-Id: I1160474dbe48478d95bfdcdd17017e808b398492
Reviewed-on: https://chromium-review.googlesource.com/968523Reviewed-by: Julian Pastarmov <pastarmovj@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Greg Thompson <grt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544854}