Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Part of https://gitlab.com/gitlab-org/gitlab-ce/issues/24899
See https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7779 and https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/7813
merged
mentioned in commit 141593fa