Add Glance client metadata to create Octavia amphora image

- Add admin_identity to create resources from admin user
- Add glance.client.init that makes sure the client is enabled
- Add Glance client metadata for an Octavia amphora image
- Add mine function to retrieve owner ID for a created image

Related prod: PROD-11910

Change-Id: I051f499ca304d270e87b4fe35bddce32e09742f1
4 files changed