Update vdev devid and physpath if changed between imports

If devid or physpath for a vdev changes between imports, ensure it is
updated to the new value.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Ameer Hamza <ahamza@ixsystems.com>
Closes #15816