GitLab

Legacy supervised users are now deprecated. This CL removes some dead
UI code and strings.

Bug: 1164090
Change-Id: I895ad42c4c336889aebb57112ca80ef622594e4e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2625803
Auto-Submit: Toby Huang <tobyhuang@chromium.org>
Reviewed-by: Denis Kuznetsov [CET] <antrim@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Toby Huang <tobyhuang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844836}