Android : Android setting development or production environment

I have an Android project that is communicating with an API. However, the API URL is hardcoded into the code.

Coming from a Rails background, it is possible to communicate to a staging server or a production server based on the Rails environment on which is defined in a config file.

I found BuildConfig.java which contains a DEBUG variable but warns:

/** Automatically generated file. DO NOT MODIFY */

How can I determine which server to communicate to with Android with best practice? Is there a config file to do so?