Add Nova client metadata to create Octavia keypair

- Added metadata defining keypair required to log-in into amphorae
- Include service.nova.client and depend on it to enable client
- Also use admin_identity to create nova flavors as this action is
  often restricted to admin

Depends on: https://gerrit.mcp.mirantis.net/7475
Related PROD: PROD-12876

Change-Id: I35b642110f3922ca6bb64e355f7cd9130db3359f
1 file changed