Add service role in Nova policy

RBAC community wide goal phase-2[1] is to add 'service'
role for the service APIs policy rule. This commit
defaults the service APIs to 'service' role. This way
service APIs will be allowed for service user only.

Tempest tests also modified to simulate the service-to-service
communication. Tempest tests send the user with service
role to nova API.
- https://review.opendev.org/c/openstack/tempest/+/892639>

Partial implement blueprint policy-service-role-default

[1] https://governance.openstack.org/tc/goals/selected/consistent-and-secure-rbac.html#phase-2

Change-Id: I1565ea163fa2c8212f71c9ba375654d2aab28330
Signed-off-by: Ghanshyam Maan <gmaan@ghanshyammann.com>

api-ref/source/parameters.yaml

@@ -7628,6 +7628,12 @@ volumeId_swap:
   in: body
   required: true
   type: string
+volumeId_update:
+  description: |
+    The UUID of the attached volume.
+  in: body
+  required: true
+  type: string
 volumes:
   description: |
     The list of ``volume`` objects.