Introduces an option to set a dump latency requirement.

We are currently dumping invalid data for pulled metrics. Pulled metrics
require a new pull when flushing a bucket. We should either do another
pull or invalidate the previous bucket.

There are cases where we cannot afford to do another pull, e.g. statsd
being killed. If we do not have enough time, we'll just invalidte the
bucket to make sure we have correct data.

Bug: 123866830
Test: atest statsd_test
Change-Id: I090127cace3b7265032ebb2c9bddae976c883771