Group on trial downgraded to Free when minutes are purchased

Bug

Summary

A group on the free Ultimate with GitLab Duo Enterprise Trial plan is downgraded to Free when minutes are purchased on the group.

This removes GitLab Duo trial but the widget that displays X days left in trial is still shown on the group.

Steps to reproduce

1. Create a GitLab group
2. Start the free Ultimate with GitLab Duo Enterprise Trial on the group
3. Go to Usage Quotas -> Pipeline tab and click on Buy additional compute minutes button
4. Purchase minutes and wait for the provisioning to complete
5. Check the Billing page in the group
   • Notice the group is on Free plan
   • Notice the trial widget still shows

What is the current bug behavior?

A group on the free Ultimate with GitLab Duo Enterprise Trial plan is downgraded to Free when minutes are purchased on the group.

What is the expected correct behavior?

Add on purchase should not interfere with the trial

Relevant logs and/or screenshots

See https://staging.gitlab.com/groups/mins-purchase-test-group/-/billings for an example of the issue.

Workarounds

Use Cdot trial extension tools to re-instate the trial

Reported examples

1. https://gitlab.zendesk.com/agent/tickets/653183
2. https://gitlab.zendesk.com/agent/tickets/655525