First of all, this is for iOS only. Google Maps is the default map source on Android devices so the Corona SDK native mapView features should be what you’re using there. However on iOS a while back, Apple removed Google Maps in favor of Apple Maps. When that happened the Corona SDK native mapView started using Apple Maps. Sometime later, after all the the grief that Apple got over their maps, they allowed Google to reintroduce their map app.
This tutorial is based on that. You have to have the Google Maps app installed on iOS and this should cause the Google Map apps to launch. It is not expected to work on Android. Android does not use URL schemes to do these types of actions. If you want to read more about this (albeit the code samples are for Objective-C) you can here:
https://developers.google.com/maps/documentation/ios/urlscheme
Rob