Add persist.heapprofd.enable property.

This is analoguous to what Perfetto does with persist.traced.enable.

Test: m
Test: flash walleye
Test: setprop persist.heapprofd.enable 1
      setprop persist.heapprofd.enable 0

Change-Id: I997272ef8c6fe078aca2388ed0cf2ecc3de612a5
4 files changed