#1201 use different application ID for debug builds

This is a minor update to #1339.

This patch will change the applicationId for debug builds as well as using "Debug Stumbler" as the app_name so that it's easy to identify release vs debug builds of the stumbler on your launcher.

I've removed the change to the versionName as I don't see any benefit to messing with versions when the applicationId is completely different anyway.