Remove install_default when install_default_upload
    
    two tests only differ by saving of qcow2 on test end for last one.
    
    That concerns ppc64le and aarch64 flavors:
        AtomicHost-dvd_ostree-iso
        Server-dvd-iso
    
    Signed-off-by: Michel Normand <normand@linux.vnet.ibm.com>