Old Man's Journey only accesses your storage to read in game relevant data from a ressource package delivered by Google Play and to store screenshots of the game.
Google Play Games Services and Google Sign-In
We use Google Play Games Services to synchronize save games between your devices. I you don't want to synchronize save files, you don't need to sign in. To manually sign out or to sign in, we provide a Google Sign-in button in the pause menu. We don't access any data of your Google account. The play experience will always be the same, even if you don't sign-in to Google!'
We have recently found out that Unity 5.6.4, which we used to build Old Man's Journey for Android, implements an interface to request a device's Android Device ID and the Advertising ID even though this was never enabled by us. This is a bug and sadly it won't be fixed in this old Unity version anymore. We don't use this interface or these IDs in Old Man's Journey whatsoever and never access them.'