GCP - VPC network not getting deleted when the environment is deleted

[devdattakulkarni]

When GKE env is created, we create a custom VPC network for the cluster (as part of cld env create).

This custom network is not getting deleted when the env is deleted (cld env delete).

In the code we are invoking appropriate SDK call, but it is not taking effect:

https://github.com/cloud-ark/cloudark/blob/master/server/server_plugins/gcloud/coe/gke.py#L81