Clear the statsd data buffer regardless of StatsdServer config
I think we should have a way to turn off statsd recording, as the
document of StatsdServer config states "If not set, statsd metrics
will not be collected.".
Bug: T329415
Change-Id: I5a76b01903449151b048c840bdf3655e233ed049
(cherry picked from commit 1fa92f2a28c14611e4d4ea93bf59979a7ff451f2)