Terraria – How to back up Terraria game saves on Android

Before updating to the new version (1.1.6292), I want to back-up the old game (the old version without hardmode – 1.04) saves.

I can't seem to find them anywhere. How could this be? If the app has permissions to write them somewhere, I should be able to read/write on that location too, shouldn't I?

I'm afraid the new version will purge my old saves. If it's not possible to update them, I'd like to keep them for sentimental reasons…