oslo policy: check puppet resource instead of actual config in spec

Change-Id: I0743932758aee9d4b6b36d8dfff179df71672689

spec/classes/nova_policy_spec.rb

@@ -20,7 +20,9 @@ describe 'nova::policy' do
         :key   => 'context_is_admin',
         :value => 'foo:bar'
       })
-      is_expected.to contain_nova_config('oslo_policy/policy_file').with_value('/etc/nova/policy.json')
+      is_expected.to contain_oslo__policy('nova_config').with(
+        :policy_file => '/etc/nova/policy.json',
+      )
     end
   end