Clarify moving of runner managers
This MR will resolve https://gitlab.com/gitlab-com/infrastructure/issues/920 by indicating what steps must be taken before you can migrate the runners using the same token.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
This MR will resolve https://gitlab.com/gitlab-com/infrastructure/issues/920 by indicating what steps must be taken before you can migrate the runners using the same token.