Goal:
Verify the Cinder multi-region fix by validating that Cinder correctly interacts with Glance, Swift (backup driver), and Barbican in a multi-region environment.

Acceptance Criteria:

• A DCN job covering multi-region scenarios is executed.
• Tempest runs successfully as part of the DCN job.
• No errors are observed related to Cinder communicating with the wrong region.
• Interactions between Cinder and Glance, Swift, and Barbican behave as expected in a multi-region setup.