Merge branch 'update-admin-background-migrations-jmiocene' into 'master'

Update admin background migrations

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/158349



Merged-by: Gavin Hinfey <ghinfey@gitlab.com>
Approved-by: Paul W <19602001-paintedbicycle-gitlab@users.noreply.gitlab.com>
Approved-by: Lorena Ciutacu <lciutacu@gitlab.com>
Approved-by: Jack Chapman <jachapman@gitlab.com>
Approved-by: Tarun Vellishetty <tvellishetty@gitlab.com>
Approved-by: Sheldon Led <sheldonled@gitlab.com>
Approved-by: Gavin Hinfey <ghinfey@gitlab.com>
Reviewed-by: Lorena Ciutacu <lciutacu@gitlab.com>
Reviewed-by: Jack Chapman <jachapman@gitlab.com>
Co-authored-by: Julia Miocene <jmiocene@gitlab.com>