Atest: add LOCAL_TEST_CONFIG to module_info.json

Bug: 112335032

Test: 1. Add LOCAL_TEST_CONFIG := ahat-tests.xml in
         art/tools/ahat/Android.mk for ahat-tests
      2. add ahat-tests.xml in local
      3. atest -m hello_world_test
      4. check module_info.json
         local_full_test_config": ["art/tools/ahat/ahat-tests.xml"]

Change-Id: Ice2a0c85979fa6b872c92aea5ff4a340342408ad