Source: https://gist.github.com/str4d/22cac7a3f70bc227cdca
License: http://opensource.org/licenses/MIT

Changing this requires changing the import path of the generated R file, which
will unnecessarily affect most of the code. R is built in a package based on
the AndroidManifest.xml package name, whereas the final app package name is
overridden in app/build.gradle for free and donate versions.