fix: ajuste no json

lib/controllers/notification_message_controller.ex

@@ -7,7 +7,7 @@ defmodule NotificationDispatcher.Controller.NotificationMessageController do
   def create(params) do
     case NotificationsContext.create_notification_message(params) do
       {:ok, notification_message} ->
-        {:ok, notification_message, "{\"data\": {\"id\": \"#{notification_message.id}\"}}"}
+        {:ok, notification_message, %{data: %{id: notification_message.id}}}
       {:error, changeset} ->
         {:error, changeset}
     end