Automatic merge from submit-queue (batch tested with PRs 53567, 53197, 52944, 49593). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
[OpenStack]Add codes to check the count of nodes(members)
After merging this PR(#53146), if there is no available nodes for
the loadbalancer service, UpdateLoadBalancer() will run panic.
**Release note**:
```release-note
NONE
```