device: Avoid clearing storage when we can garbage collect
If the device supports listing prints, then we can do more targeted deletes once the storage runs out. As such, do not try to clear the storage on first enroll (therefore allowing dual boot setups to work to a limited degree).
Need to update the tests (basically, revert the changes again). Maybe we'll want a another virtual device or a way to enable/disable the list
functionality.
CC: @vincenth
Edited by Benjamin Berg