Perform update for duration metric

Creates a new metric if the metric is new/needs replacement.
Preserves the metrics that can be preserved. Ensures that indices are
updated, including within duration trackers.

Does not handle if a condition is true for a new metric based on an
existing condition.

Test: atest statsd_test
Bug: 162323124
Change-Id: Ibe0baf54678c1c6efde5aeba6a4b9b7fa2634c55