CCMA Group Page restrictions are dropped with scoped user/group migration if the group does not have space permissions

Issue Summary

Based on https://jira.atlassian.com/browse/MIG-1644 

This is reproducible on the Data Center: Yes

Migration Type: server to cloud 

when we migrate scoped users and groups in CCMA, groups associated with page restriction are not migrated if the group does not also have space permissions. The group is still referenced in the restrictions on the cloud even though we couldn't find it in the Administration.

Steps to Reproduce

1. On Confluence server Create a Page inside a space
2. Put a Restriction on a Page with a Group with few users
3. Create a Migration Plan->Add the Space with Restricted page-> Select Only Users related to selected spaces-> Run The Migration
4. Once Migration is complete, go to cloud site and check for the Group associated with the restriction on the page and it is not available

Expected Results

All groups associated with page restriction should be migrated to cloud site and have access to the Page as per restrictions

Actual Results

No Groups are Migrated to the cloud if they are a part of the Restriction on a Confluence Page

Workaround

Migrate all users and groups with the migration

or

Re-add the age restrictions manually