aaa: Change builtin authenticators and directories initialization

The following patch changes the logic in which the builtin
authenticators and directories are initialized :
Properties objects are created them and passed to ExtensionManager
for loading

Change-Id: Id8513cb992c5becef7e83c04a8da8bc7f1622348
Topic: AAA
Signed-off-by: Yair Zaslavsky <yzaslavs@redhat.com>