Sebastien Blanc Erik Jan de Wit besides the above, it also is able to take in other metadata, like alias, see here:

https://aerogear.org/docs/guides/aerogear-cordova/AerogearCordovaPush/ (search for push-config.json)

Unfortunately the linked documentation does not even speak about the JSON file:
https://github.com/aerogear/aerogear-cordova-push#documentation