Google Play Games with Google App Engine

[Hasam via StackOverflow]

I have an Android App up and running using Google Play Services (for real time multiplayer). I would like to use Google App Engine with this project, I was looking at the Youtube video for Google's Mobile Backend Starter. When I open the Cloud Console and try to deploy my existing app, this is what shows up:

So I'm wondering if there is a way to use GAE in my existing app. Thanks.

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