tp: Improve error message for RUN_METRIC substitution
tp: Improve error message for RUN_METRIC substitution

On substitution failures, print the line that had problems.

Change-Id: I1aa69e123641b81fd449e93d1b4f3d185c732e28
google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto