Add Retention Duration to google_pubsub_topic

mmv1/products/pubsub/api.yaml

@@ -100,6 +100,16 @@ objects:
               - :ENCODING_UNSPECIFIED
               - :JSON
               - :BINARY
+      - !ruby/object:Api::Type::String
+        name: 'messageRetentionDuration'
+        description: |
+          Indicates the minimum duration to retain a message after it is published
+          to the topic. If this field is set, messages published to the topic in
+          the last messageRetentionDuration are always available to subscribers.
+          For instance, it allows any attached subscription to seek to a timestamp
+          that is up to messageRetentionDuration in the past. If this field is not
+          set, message retention is controlled by settings on individual subscriptions.
+          Cannot be more than 7 days or less than 10 minutes.
   - !ruby/object:Api::Resource
     name: 'Subscription'
     description: |

mmv1/templates/terraform/examples/pubsub_topic_basic.tf.erb

@@ -4,4 +4,6 @@ resource "google_pubsub_topic" "<%= ctx[:primary_resource_id] %>" {
   labels = {
     foo = "bar"
   }
+
+  message_retention_duration = "86600s"
 }