Revert "Remove obsolete TestApiEnforcementPolicy." This reverts commit d8b153b7c2026f45db97a7fd5804957becc5cfdf. Reason for revert: cts tests on -user builds is broken Change-Id: I7528fb6d1606f08d2398bc4cbb27519424cf1b51 (cherry picked from commit 09efc1604936c234b65a5d278f5ea63da29b17cd)