So, I've tried it myself and I am pretty sure that you just have to delete the old version and then install the new one. That should take care of the problem. I can't say more, this problem hasn't happened to any of my patrons or on other forums so I don't have a better solution right now.
Don't worry about the questions, I want to help, I am just an android noob as well : ) On PC the saves are stored separate from the game so you can just deinstall and install a new version and the saves will work, but I am not 100% sure if that is the case for Android.
