The installer uses HTTP HEAD to validate if user-provided service endpoint URLs are reachable. However, in some cases, the request results in a redirect to AWS doc URL, which can causes install failure in disconnected environment. The users should not be required to open access to AWS docs to install.

For example:
$ curl --head https://sts.ap-southeast-1.amazonaws.com HTTP/1.1 302 Found
Location: https://aws.amazon.com/iam
This requires internet connection making installation of openshift in disconnected environment challenging

pull request: https://github.com/openshift/installer/pull/10360