Disable automount on KDE live images (#2073708)
    
    It's mounting non-removable devices and causing problems for
    anaconda. Note, KDE will still show a notification with a
    button for mounting the device, and it shows in the file manager
    where clicking on it mounts it; the behaviour is about the same
    as Fedora 35 (slightly better, as the notification shows on
    subsequent plugs of the same stick, which it did not in F35).
    
    Signed-off-by: Adam Williamson <awilliam@redhat.com>