Revert using service role for nova user

Looks like nova still needs admin role to work.  This is probably
a security bug against nova, but that's being debated.  So, in the
mean time, need to revert this back to using admin role.

Change-Id: If8b58516032f2eb5f9782189744f22abc4ab40b5
Related-Bug: #1436050

attributes/default.rb

@@ -67,7 +67,7 @@ end
 
 default['openstack']['compute']['service_tenant_name'] = 'service'
 default['openstack']['compute']['service_user'] = 'nova'
-default['openstack']['compute']['service_role'] = 'service'
+default['openstack']['compute']['service_role'] = 'admin'
 
 case platform_family
 when 'fedora', 'rhel', 'debian'

recipes/identity_registration.rb

@@ -64,8 +64,8 @@ openstack_identity_register 'Register Service User' do
   action :create_user
 end
 
-## Grant Service role to Service User for Service Tenant ##
-openstack_identity_register "Grant 'service' Role to Service User for Service Tenant" do
+## Grant Admin role to Service User for Service Tenant ##
+openstack_identity_register "Grant 'admin' Role to Service User for Service Tenant" do
   auth_uri auth_uri
   bootstrap_token bootstrap_token
   tenant_name service_tenant_name

spec/identity_registration_spec.rb

@@ -33,15 +33,15 @@ describe 'openstack-compute::identity_registration' do
       )
     end
 
-    it 'grants service role to service user for service tenant' do
+    it 'grants admin role to service user for service tenant' do
       expect(chef_run).to grant_role_openstack_identity_register(
-        "Grant 'service' Role to Service User for Service Tenant"
+        "Grant 'admin' Role to Service User for Service Tenant"
       ).with(
         auth_uri: 'http://127.0.0.1:35357/v2.0',
         bootstrap_token: 'bootstrap-token',
         tenant_name: 'service',
         user_name: 'nova',
-        role_name: 'service'
+        role_name: 'admin'
       )
     end