Adding New IAM Policy for Cluster Autoscaler

[olamide005]

The Autoscaler's version was updated to the penultimate chart here:
#407

The worker running the cluster autoscaler needs access to certain resources and actions for new versions and its configuration as suggested here: https://github.com/kubernetes/autoscaler/tree/master/charts/cluster-autoscaler#additional-configuration

The up-to-date IAM permissions required, is gotten from the cluster autoscaler's AWS Cloudprovider Readme (selecting the tag of the cluster autoscaler image in use): https://github.com/kubernetes/autoscaler/blob/cluster-autoscaler-chart-9.24.0/cluster-autoscaler/cloudprovider/aws/README.md

Terragrunt Apply

Terraform will perform the following actions:

  # aws_iam_policy.cluster_autoscaler will be updated in-place
  ~ resource "aws_iam_policy" "cluster_autoscaler" {
        id          = "arn:aws:iam::***:policy/cluster-autoscaler-ops20230106164844398400000001"
        name        = "cluster-autoscaler-ops20230106164844398400000001"
      ~ policy      = jsonencode(
          ~ {
              ~ Statement = [
                  ~ {
                      ~ Action   = [
                            "ec2:DescribeLaunchTemplateVersions",
                          + "ec2:DescribeInstanceTypes",
                            "autoscaling:DescribeTags",
                          + "autoscaling:DescribeScalingActivities",
                            "autoscaling:DescribeLaunchConfigurations",
                            # (2 unchanged elements hidden)
                        ]
                        # (3 unchanged elements hidden)
                    },
                  ~ {
                      ~ Action    = [
                          + "eks:DescribeNodegroup",
                          + "ec2:GetInstanceTypesFromInstanceRequirements",
                          + "ec2:DescribeImages",
                            "autoscaling:UpdateAutoScalingGroup",
                            # (2 unchanged elements hidden)
                        ]
                        # (4 unchanged elements hidden)
                    },
                ]
                # (1 unchanged element hidden)
            }
        )
        tags        = {}
        # (6 unchanged attributes hidden)
    }

Plan: 0 to add, 1 to change, 0 to destroy.
aws_iam_policy.cluster_autoscaler: Modifying... [id=arn:aws:iam::***:policy/cluster-autoscaler-ops2023010[61](https://github.com/exact-payments/gruntwork-infrastructure-live/actions/runs/4407376954/jobs/7720963363?pr=1524#step:16:62)[64](https://github.com/exact-payments/gruntwork-infrastructure-live/actions/runs/4407376954/jobs/7720963363?pr=1524#step:16:65)[84](https://github.com/exact-payments/gruntwork-infrastructure-live/actions/runs/4407376954/jobs/7720963363?pr=1524#step:16:85)4398400000001]
aws_iam_policy.cluster_autoscaler: Modifications complete after 0s [id=arn:aws:iam::***:policy/cluster-autoscaler-ops20230106164844398400000001]
Releasing state lock. This may take a few moments...

Apply complete! Resources: 0 added, 1 changed, 0 destroyed.