For reasons that I have no control over, I can't use other APIs and I need to stick to EXTERNAL write and read permission with no ACCESS all files. This means, in the internal storage, our app can generate files but cannot access any other files inside that same directory that our app didn't create.
We are trying to release an update, however I am afraid that once the app is updated users will lose permission to the files they created in the previous version. Is that possible or does Android know that the app is only updated and doesn't revoke any permission?