We should have a high-density test running on regular GCE

Currently we have only one running on kubemark - https://github.com/kubernetes/test-infra/blob/master/config/jobs/kubernetes/sig-scalability/sig-scalability-periodic-jobs.yaml#L276

Start by reviewing config/jobs/kubernetes/sig-scalability/sig-scalability-periodic-jobs.yaml at the referenced kubemark job. Trace how that high-density test is configured and identify what is needed for an equivalent job on regular GCE. Done means a regular-GCE high-density test is configured and covered by the repository's relevant validation.

Written by the indexing model from the issue text.