Statsd can dump data as proto to bugreport

* Creates an incident section for statsd data.
* Allows dump to output statsd data, in proto format.
* Hooks up two statsd outputs to bugreports:
  -statsd report data in proto format
  -statsd metadata (statsdstats) in text format

The incident section does not import stats_log.proto because that turns
out to be extremely difficult: stats_log.proto imports atoms.proto,
which imports more things and is enormous and causes all sorts of
problems. atoms.proto was purposefully never compiled in AOSP, so to
retain that feature, the incident section uses 'bytes' instead of an
actual message. Since this isn't ever read in AOSP (other than testing),
this should be fine.

Bug: 115678461
Test: take a bug report and confirm valid proto
Test: cts-tradefed run cts-dev -m CtsStatsdHostTestCases -t android.cts.statsd.atom.HostAtomTests#testDumpsysStats

Change-Id: I1c370af7678d1dc7440ce299ea5ea4da6d33832b