Confirm occupied IP ranges are released in Cleanup of GKE cluster

[randmonkey]

Is there an existing issue for this?

• I have searched the existing issues

Problem Statement

As described in Kong/kubernetes-ingress-controller#3326, gcloud limited number ofIP ranges in a subnet. To prevent failures caused by the limit of IP range, we should confirm that occupied ranges is released after the Cleanup of cluster is finished,

Proposed Solution

• Verify whether occupied IP ranges is released after successfully cleaned up the cluster in GKE
• If not guaranteed that occupied IP ranges is released after cleanup of cluster, we add poll and wait step in cluster cleanup after calling API to delete cluster.

Additional information

No response

Acceptance Criteria

• For GKE cluster, IP ranges (and possibly other resource with limitations) are released after clean up of cluester succeeded.