Tweak to the events API schema

Author: rjuliano

src/integ_test_resources/android/amplify/integration/cdk/schemas/api_tests/events_api.graphql

@@ -8,13 +8,17 @@ type Event @model {
 }
 
 type Comment @model {
-  id: ID!
-  eventId: String!
-  content: String!
-  createdAt: AWSTimestamp!
+	eventId: ID!
+	commentId: String!
+	content: String!
+	createdAt: String!
   event: Event @connection(name: "EventComments")
 }
 
+type Mutation {
+  commentOnEvent(eventId: ID!, content: String!, createdAt: String!): Comment
+}
+
 type Subscription {
     subscribeToEventComments(eventId: String!): Comment @aws_subscribe(mutations: ["createComment"])
 }