kubetest2-eks add node ASG configuration

```
AWS_K8S_TESTER_EKS_ADD_ON_NODE_GROUPS_ASGS='{"GetRef.Name-ng-al2-cpu":{"name":"GetRef.Name-ng-al2-cpu","remote-access-user-name":"ec2-user","ami-type":"AL2_x86_64","image-id":"","image-id-ssm-parameter":"/aws/service/eks/optimized-ami/1.17/amazon-linux-2/recommended/image_id","instance-types":["c5.xlarge"],"volume-size":40,"asg-min-size":2,"asg-max-size":2,"asg-desired-capacity":2,"kubelet-extra-args":""},"GetRef.Name-ng-al2-gpu":{"name":"GetRef.Name-ng-al2-gpu","remote-access-user-name":"ec2-user","ami-type":"AL2_x86_64_GPU","image-id":"","image-id-ssm-parameter":"/aws/service/eks/optimized-ami/1.17/amazon-linux-2-gpu/recommended/image_id","instance-types":["p3.8xlarge"],"volume-size":40,"asg-min-size":1,"asg-max-size":1,"asg-desired-capacity":1,"kubelet-extra-args":""},"GetRef.Name-ng-bottlerocket":{"name":"GetRef.Name-ng-bottlerocket","remote-access-user-name":"ec2-user","ami-type":"BOTTLEROCKET_x86_64","image-id":"","image-id-ssm-parameter":"/aws/service/bottlerocket/aws-k8s-1.15/x86_64/latest/image_id","ssm-document-cfn-stack-name":"GetRef.Name-install-bottlerocket","ssm-document-name":"GetRef.Name-InstallBottlerocket","ssm-document-create":true,"ssm-document-commands":"enable-admin-container","ssm-document-execution-timeout-seconds":3600,"instance-types":["c5.xlarge"],"volume-size":40,"asg-min-size":2,"asg-max-size":2,"asg-desired-capacity":2}}'
```

We need to set the above environment variable and set the instance-type and the ASG sizing.