Update terraform/test.secure_agent.tfvars, terraform/network.tf, terraform/autoscaling-group.tf, terraform/efs.tf

This volume will act as the persistence storage for Secure Agent's logs and configurations.

Since our licensing restrict us from more than 1 instance of Secure Agent, before deploying a new instance existing instance need to be shutdown (after adjusting any resources that depends on that instance). Due to this reason terraform is not part of CI/CD.