Use yaml instead of json for policy file

Because usage of json for policy file will be deprecated and replaced
by yaml[1].

[1] https://governance.openstack.org/tc/goals/selected/wallaby/migrate-policy-format-from-json-to-yaml.html

Depends-on: https://review.opendev.org/769647
Change-Id: I2d1dc5791f18d10e9947f962b796872e7d6990e1

manifests/policy.pp

@@ -20,12 +20,12 @@
 #   Defaults to empty hash.
 #
 # [*policy_path*]
-#   (Optional) Path to the nova policy.json file
-#   Defaults to /etc/nova/policy.json
+#   (Optional) Path to the nova policy.yaml file
+#   Defaults to /etc/nova/policy.yaml
 #
 class nova::policy (
   $policies    = {},
-  $policy_path = '/etc/nova/policy.json',
+  $policy_path = '/etc/nova/policy.yaml',
 ) {
 
   include nova::deps
@@ -37,6 +37,7 @@ class nova::policy (
     file_path   => $policy_path,
     file_user   => 'root',
     file_group  => $::nova::params::group,
+    file_format => 'yaml',
   }
 
   create_resources('openstacklib::policy::base', $policies, $policy_defaults)

releasenotes/notes/migrate-policy-format-from-json-to-yaml-878c644d4a059c3e.yaml

@@ -0,0 +1,4 @@
+---
+upgrade:
+  - |
+    Now policy.yaml is used by default instead of policy.json.

spec/classes/nova_policy_spec.rb

@@ -5,7 +5,7 @@ describe 'nova::policy' do
   shared_examples_for 'nova policies' do
     let :params do
       {
-        :policy_path => '/etc/nova/policy.json',
+        :policy_path => '/etc/nova/policy.yaml',
         :policies    => {
           'context_is_admin' => {
             'key'   => 'context_is_admin',
@@ -21,9 +21,10 @@ describe 'nova::policy' do
         :value       => 'foo:bar',
         :file_user   => 'root',
         :file_group  => 'nova',
+        :file_format => 'yaml',
       })
       is_expected.to contain_oslo__policy('nova_config').with(
-        :policy_file => '/etc/nova/policy.json',
+        :policy_file => '/etc/nova/policy.yaml',
       )
     end
   end