docs: document RUN_METRIC am: 6dad5a0ed7
docs: document RUN_METRIC am: 6dad5a0ed7

Original change: https://android-review.googlesource.com/c/platform/external/perfetto/+/1878368

Change-Id: I848fc7cbb08fbc7f2dc0d7d89b66e436feb1e9fc

google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto