Refactor determine metric update status

Refactor and create a generic determineMetricUpdateStatus() function
that works for all metrics. Will simplify the process of determining
if a metric needs an update for all future metric types.

Test: atest statsd_test
Bug: 168863134
Change-Id: If89e1625cf7536406fbd168aca63193d5e9a908f
3 files changed