Workload identity support for GKE cluster creation

Currently cluster created using XPK are setup using the default compute service account and assign some scopes for the service account. Its recommended to use workload identity as its more scoped and granular and is also the recommended way to access gcp resources.
https://docs.cloud.google.com/kubernetes-engine/docs/concepts/security-overview#access-gcp-resources

Existing path using
https://docs.cloud.google.com/kubernetes-engine/docs/how-to/access-scopes

Workload Identity
https://docs.cloud.google.com/kubernetes-engine/docs/how-to/workload-identity