tp: reference the need to edit the index file in add_tp_diff_test
tp: reference the need to edit the index file in add_tp_diff_test

Change-Id: If0392b5f1618a6ec103c21b2ebb786f93c325710
google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto