Testdrive: allow multiple atoms in pulled atoms

Modifies statsd_testdrive to allow up to 100 atoms to be pulled at a
time. Uses trigger event with app breadcrumb so that the puller happens
once.

Bug: 128893770
Test: statsd_testdrive 10021 (temperature)
Change-Id: I185a7eb1b32a6b19596601dcf5a1ba7a633e4e35