Fix branch-based caching of unparsed config

This fixes two problems:

* We were using an UnparsedTenantConfig object to cache the previously
  parsed config for use in reconfigurations (static or dynamic).  But
  in the dynamic config path, we would end up passing that back into
  the yaml parser.  Skip that step.
* That cached data was for the whole project, but we are assembling
  the config one project-branch at a time.  Since we have other areas
  that use the full project config, keep that, but also cache the
  UnparsedTenantConfig for each project-branch.

Change-Id: Ie3c95cb2236b517d28bec45590c9eea6c1802008
2 files changed