custom-device interface: 'files' is not 'list' lint-snap-v2_slots_attributes

[Alex Lewontin]

For the following snippet of snap.yaml:

  mycustomdevice:
    interface: custom-device
    custom-device: mycustomdevice
    devices: [ /dev/my-custom-device ]
    files:
      write:
        - /etc/foo
        - /etc/bar

upload to the store fails with the message

 'files' is not 'list' lint-snap-v2_slots_attributes (mycustomdevice, files)

Per snapd source, it looks like 'files' should not be a list, but rather a dict with keys 'read' and 'write', each of which should be a list.

[Alex Murray (alexmurray)]

Thanks - I have merged the MR, tagged a new release (https://git.launchpad.net/review-tools/tag/?h=20221010-0140UTC) and asked the snap store team to update to this new version.