Automatic merge from submit-queue (batch tested with PRs 39029, 39014)
[Glusterfs Vol Plugin]: Check kube client is invalid and return error
Fixes: #38939
In volume plugins, we need to create a kube client to make api call. And this kube client can be nil when, for example, wrong api-server configuration, but kubelet should not crash in this case.
I have also checked other plugins and found only glusterfs need this fix.
1c2a23e48c