Made Ambari RPM location configurable

The Ambari RPM location is now an ambari configuration property in
the blueprint.  This will support debug/issue resolution scenarios
as well as the export of this information.

Fixes:  bug #1208966

Change-Id: Ie0bfbd39d687c8c26d654b7fcfb369f764d48ef2
Merge "Made Ambari RPM location configurable"