Fix crash when exporting key file from internal storage.
This is the first release for which the offline/nonet variant is released also after upgrading the app to .net for Android. Note: the offline variant is a preliminary build as it currently cannot be installed side-by-side with the regular version. Also, apk size is much larger than needed. (The apk contains all libraries from the version with internet access.). As of now, this nonet build does not include the feature to scan QR codes for TOTP, because MLKit (which is used in the regular version) requests internet permission.
Please note: there was a "v1.12-r8" as Github release which contained an incorrect build of the NoNet variant and therefore was deleted. Please update to r8c if you have installed r8.