Add EKS_ARM64 target for containerinsight_eks_prometheus test case.

[bryan-aguilar]

See PR #1002 for changes that had to be reverted. A previous attempt was made to update the platforms that this test case was ran against. Updating the images tags by adding the -latest suffix to the tag caused the test to fail. On AMD64 clusters the failure was listed as

 module.validator.null_resource.validator (local-exec): validator_1  | com.amazon.aoc.exception.BaseException: [ContainerInsight] metric catalina_manager_rejectedsessions not found with dimension [ClusterName: collector-ci-amd64-1-21, Namespace: jmx-1c92828513181efe]

The images listed in PR #1002 must be investigated further before being rebuilt. There origin is a bit unknown and we don't have explicit steps for rebuilding/redeploying them to ECR. This doc may prove to be a good starting point.

These images must also be built multiplatform after being updated.