Reverse switch statement to avoid needing to change for each new vers…

[nift4]

…ion (and modernize build system)

[nift4]

Unless there are unexpected surprises, this should be enough to support Android 15 (and maybe all others after that, too).

[nift4]

Test APK: https://github.com/nift4/FakeGApps/releases/download/pr1/app-release.apk

[novakovicdavid]

Can build & confirm it still works fine. It's nice to be able to build the project without jumping through hoops.

Thank you again for the work. I'll merge it once the above remark is resolved.