Merge branch '463854-import-sharding-bulk_import_exports' into 'master'

Create multi not null constraint for exports

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/168411



Merged-by: Alper Akgun <aakgun@gitlab.com>
Approved-by: Alper Akgun <aakgun@gitlab.com>
Reviewed-by: Alper Akgun <aakgun@gitlab.com>
Reviewed-by: Brian Williams <bwilliams@gitlab.com>
Co-authored-by: Keeyan Nejad <knejad@gitlab.com>