Add task stop verification ack to ecs-agent module

Author: ohsoo

ecs-agent/acs/session/task_stop_verification_ack renamed to agent/vendor/github.com/aws/amazon-ecs-agent/ecs-agent/acs/session/task_stop_verification_ack_responder.go

@@ -63,6 +63,9 @@ func (r *taskStopVerificationACKResponder) handleTaskStopVerificationACK(message
 		return errors.New("Invalid messageID received: " + ackMessageID + " Manifest Message ID: " + manifestMessageID)
 	}
 
+	// Reset the message id so that the message with same message id is not processed twice.
+	r.messageIDAccessor.SetMessageID("")
+
 	// Loop through all tasks in the verified stop list and set the desired status of each one to STOPPED.
 	tasksToStop := message.StopTasks
 	for _, task := range tasksToStop {

agent/vendor/github.com/aws/amazon-ecs-agent/ecs-agent/metrics/constants.go

@@ -26,4 +26,9 @@ const (
 	// AttachResourceResponder
 	attachResourceResponderNamespace = "ResourceAttachment"
 	ResourceValidationMetricName     = attachResourceResponderNamespace + ".Validation"
+
+	// TaskManifestResponder, TaskStopVerificationACKResponder
+	taskManifestResponderNamespace = "TaskManifestResponder"
+	TaskStoppedMetricName          = taskManifestResponderNamespace + ".TaskStopped"
+	TaskManifestHandlingDuration   = taskManifestResponderNamespace + ".Duration"
 )