The share instance doesn't have pool value in host property,
We cannot update share instance pool when we restart manila
share service, becuase we use share_update DB function to update
share instance attribute. Now we are changing share_update to
share_instance_update.
Change-Id: Ief7e70103ed63bbb2f78d0f9eed8351f8470d414
Closes-Bug: #1684032