The 'device_id' property was added in qemu-4.0. Since upcoming patch
will be modernizing all disk test cases we specifically want to preserve
the instance of 'device_id' not being used with qemu-3.1 and earlier.
Change the 'disk-cache' and 'disk-shared' cases to have a qemu-3.1 and a
qemu-4.1 version for testing pre-'device_id' and pre-blockdev scenarios.
Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
