Security policies from the new parent group are not applied after the group is transferred

Summary

When a group is transferred to an another group which has security policies, the projects within the group does not have approvals enforced from the new group's security policies.

Steps to reproduce

• Create a group (group-a) with MR approval policy
• Create a new group(group-b) in a different hierarchy and create a project within the group
• Create a MR in the new project
• Transfer the new group (group-b) to the first group (group-a)
• Observe that the MR in the project does not have approval rules from the first group (group-a)

Example Project

• https://gitlab.com/gitlab-org/security-risk-management/security-policies/team-member-environment/sashis-test-group/sub-group/project-a/-/merge_requests/1

What is the current bug behavior?

Policies are not synced from the new group

What is the expected correct behavior?

Policies should be applied to the new group

Relevant logs and/or screenshots

Output of checks

Results of GitLab environment info

Expand for output related to GitLab environment info

(For installations with omnibus-gitlab package run and paste the output of:
`sudo gitlab-rake gitlab:env:info`)

(For installations from source run and paste the output of:
`sudo -u git -H bundle exec rake gitlab:env:info RAILS_ENV=production`)

Results of GitLab application Check

Expand for output related to the GitLab application check

(For installations with omnibus-gitlab package run and paste the output of:
sudo gitlab-rake gitlab:check SANITIZE=true)
(For installations from source run and paste the output of:
sudo -u git -H bundle exec rake gitlab:check RAILS_ENV=production SANITIZE=true)
(we will only investigate if the tests are passing)

Possible fixes

Patch release information for backports

If the bug fix needs to be backported in a patch release to a version under the maintenance policy, please follow the steps on the patch release runbook for GitLab engineers.

Refer to the internal "Release Information" dashboard for information about the next patch release, including the targeted versions, expected release date, and current status.

High-severity bug remediation

To remediate high-severity issues requiring an internal release for single-tenant SaaS instances, refer to the internal release process for engineers.