Start statsd before starting zygote

- zygote needs statsd for logging boot time event.
- statsd starting later leads into stats logging failure which
  is reported by all child processes of zygote later.
  This brings lots of noise in statsd error.

Bug: 159664734
Test: reboot and check if error log does not show up
  E statsd  : Found dropped events: 1 error -19 last atom tag 240 from uid 10169
Change-Id: Ie585febb50a9668671c8fda41a872595baae8385