Add in example test/configs/preparer to set precedent as well as normal
project stuff (makefiles, readmes, etc) to get things building (and to
also make sure build files work).

BUG:36556899
Test: Built and started tf with seeded config and test.
Change-Id: Ia8eb408da272c424f626c8f77a91bb0eed6a656a
(cherry picked from commit 68af8b89)