Loader associated with Unknown type of a transformer kustomize plugin
and considered 'builtin'. Kustomize plugin system executes Config and
Transform method of builtin plugins. Therefore appropriate methods
of the document plugin loaders are executed as well. Main goal for
airship document plugin loaded is to determine desired aitship plugin
based on Kind field and execute its Config or Transform methods
Change-Id: Ic26a880570491ac3a59f2357ed455a2a7362387b
b1361e05f8