NAP connections are a bit special, in that they also have a [bridge]
setting, but their connection.type is "bluetooth".

The canonical way to check whether a bluetooth connection is of NAP type
is by calling _nm_connection_get_setting_bluetooth_for_nap().

So, instead of checking for bluetooth.type "pan" or "dun", check the
opposite and whether the connection is of NAP type. In practice it's the
same, but let'check for NAP consistently via get_setting_bluetooth_for_nap().