Otherwise gradle pulls in newer versions of some libraries that require
a newer Kotlin version at runtime and then make the app crash.
This also moves the dependency declarations into a dedicated file.
The implementation is rudimentary for now.
E.g. The notification is only shown when a device init fails
which seems to be triggered after the first failure.
* to get rid of global state
* to have a testable architecture
* to allow for authenticated encryption
* to have a backup format version
* to potentially allow for other storage plugins
