[ATF integration] include validator in layoutlib

After discussion we decided this makes the most sense. Validator cannot
really live outside layoutlib due to its deps to temp framework.

Bug: 150331000
Test: Tested local built, tested against studio, Decompiled jar file to
check atf existance

Change-Id: I08d7a6002cfb89bb95718d53c938457c6c9d9b71
(cherry picked from commit c693a1ef32f77c187add8b4b422b188f1766380e)
2 files changed