Merge branch 'ms-add-sd-custom-email-reply-address' into 'master'

Adds Service Desk custom email reply address

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/131270



Merged-by: Vitali Tatarintev <vtatarintev@gitlab.com>
Approved-by: Vitali Tatarintev <vtatarintev@gitlab.com>
Co-authored-by: Marc Saleiko <msaleiko@gitlab.com>