Merge branch '438708-policies-experimental-features-button' into 'master'

Add experiment promotion banner for security policies

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/144078



Merged-by: Alexander Turinske <aturinske@gitlab.com>
Approved-by: Julia Miocene <jmiocene@gitlab.com>
Approved-by: Ammar Alakkad <aalakkad@gitlab.com>
Approved-by: Alexander Turinske <aturinske@gitlab.com>
Reviewed-by: Ammar Alakkad <aalakkad@gitlab.com>
Co-authored-by: Artur Fedorov <afedorov@gitlab.com>