Where are the android save files located? Or is it tied to the APK?
They aren't tied to the apk, but they are on a hidden inaccessible folder.
They only way to see that folder is by rooting your phone and using an advanced file explorer like ES (it has an option to access that kind of files, but in only works with root access).
-EDIT- To resume, it's complicated, just don't uninstall the game.