Remove install package step from traf-pub jobs

Packaging & staging installer was moved to separate job. This job no longer
prepares git repo of install. This install-pkg step continued to
work on machines where the git repo previously existed, but fails on new
machines where the install repo had never been cloned.

Change-Id: Ibb72a9c9cc9fb25e9037f20d4ec3835870b022ee