Wait for emulator to boot before running tests
Wait for emulator to boot before running tests

We should wait for the emulator to finish booting before running tests
to avoid flakes like:
https://travis-ci.org/catapult-project/perfetto/builds/287228461

Bug: 67765711
Change-Id: I033a864d441f9e12d1aa4284aff385f44d50473a

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