Obsolete build syntax in build.gradle file.

[Dheeraj Nair]

Hi!

The build.gradle file contains some obsolete syntax for the compilation of the different parts of the Android application. If you are willing, I would like to love to submit a PR to update them to latest syntax versions.

Thanks.

Regards,
Dheeraj Nair

[Arno Puder]

PRs are always welcome! :)