Android push notifications with GCM and various products

I have an Android app containing 10 different apps and I need to send push notifications targeting specific tastes. I worked with one of them using the official google documentation - using the google-services.json file at the root of my project. I know I will need one google-services.json file for each of these flavors (since they are actually different applications), but the problem is where to put these different files, as this should go to the root of the project. not the root of each particular flavor. Has anyone had a similar problem before and found a way to handle it?