heap profile script: Make default duration very long. am: 591fe49d12
heap profile script: Make default duration very long.
am: 591fe49d12

Change-Id: Icc3ef1e37cea42ca0699cd7b63b1243addb207cd

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