add ulimit test in Dockerfile.kubetest2

Issue #, if available:

Description of changes:

Build binary for newly added e2e test which will be used to compare all resrouces limit using ulimit to make sure the resource limits is unchanged.
Newly added ulimit test PR: https://github.com/aws/aws-k8s-tester/pull/420

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

aws / aws-k8s-tester