statsd implementation of USB port overheat event reporting

Bug: 119200347
Test: su 0 ./stats_client -u
Test: Observed USB port overheat event in statsd logs
Change-Id: Ic8801417c54c118e10bb9b631d8e77d68a65c799
Signed-off-by: Maggie White <maggiewhite@google.com>
5 files changed