In [1], we are supporting shelve/unshelve the instance with accelerators
bonded, but we missed to deal the interval for polling shelved instances
to offload periodic task, so we should add the 'accel_uuids' support
in _poll_shelved_instances() periodic task.
[1]https://review.opendev.org/c/openstack/nova/+/729563/
Co-Authored-By: Wenping Song <songwenping@inspur.com>
Closes-Bug: #1917592
Change-Id: I2ba69d0d727cc183f4a5dc52eaf4000962caeb4a