There is/was a long-standing bug on Android that as far as I can tell Google never completely fixed (though I might be wrong). For apps that have both an .APK and .OBB file, the Play Store would save the .OBB file to the user's device with the incorrect file owner. This would cause the app to fail (or at least the app wouldn't see the .OBB file already there and would, I think, re-download it). The workaround involved requiring the app developer to ask for this permission, even though their actual app didn't need it, in order to avoid this issue. ANother workaround was to ask users to reboot their phone, since (I think) the permission would be corrected after a reboot (not sure, didn't delve too deeply into that in particular).
For those that are unfamiliar - .APK files are the application packages and they're limited in size by the Google Play Store. To get around the size limit, developers can create a larger .OBB file that they could host on Play (I think?) but then have to download. Google then implemented automatic downloading of the .OBB file by the Play Store, but as far as I can tell never got it right. The whole thing seems to be getting superceded by a new format called AAB (Android Application Bundle).
See: https://issuetracker.google.com/issues/37544273
Followed by: https://issuetracker.google.com/issues/37075181
For some context: https://forum.unity.com/threads/android-app-bundle-how-to-up...