merge request assigned to group for approval does not create todo for each user

Summary

When opening a merge request and assigning it to a group for review/approval, todos are not placed in the affected users' todo lists.

Steps to reproduce

• Create a merge request in a project with required approvals set to 1 or more
• Assign a group as approver
• Check any group member's todo list

What is the current bug behavior?

No todos are created

What is the expected correct behavior?

Each user should have a todo in their list. This would be the same behavior as if the MR was assigned to the user directly, and the behavior which is implied by the docs.

System Information

We are running GitLab Enterprise Edition 9.0.2-ee 3ed62189 from the omnibus package on Amazon Linux.