Mark managed-user-profile-notice as legacy

This is step 1 of replacing the notice with a newer UI.
Screenshot: http://screen/8ainJRbAfaLWqHt

Bug: 332735128
Change-Id: I3c20d70b1623ddd93854aaeaf696eab4c7c7ba56
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5419755


Reviewed-by: David Roger <droger@chromium.org>
Commit-Queue: Yann Dago <ydago@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1283164}