Google端点和Google Cloud Messaging

I am building a mobile app with a backend using google app engine, I'm using google endpoints for API calls. Now what I am wondering is if there is a possibility to use GCM on the same backend. At the beginning When I wanted to create a new module using android studio, I only found the possibility to create a backend with endpoints and another one with GCM, but nothing with both of them. Any clue? Thanks.I am building a mobile app with a backend using