1/ Use FieldMatcher to specify the value fields in value metric.
2/ rename number_of_buckets as num_buckets
3/ use double for the Alert's threshold

Test: statsd unit tests passed.
Change-Id: Id1f55f14d3712eddee561681e3cd77343f086c7a
diff --git a/cmds/statsd/tests/metrics/GaugeMetricProducer_test.cpp b/cmds/statsd/tests/metrics/GaugeMetricProducer_test.cpp
index cde50c1..749cf26 100644
--- a/cmds/statsd/tests/metrics/GaugeMetricProducer_test.cpp
+++ b/cmds/statsd/tests/metrics/GaugeMetricProducer_test.cpp
@@ -199,7 +199,7 @@
     alert.set_id(101);
     alert.set_metric_id(metricId);
     alert.set_trigger_if_sum_gt(25);
-    alert.set_number_of_buckets(2);
+    alert.set_num_buckets(2);
     sp<AnomalyTracker> anomalyTracker = gaugeProducer.addAnomalyTracker(alert);
 
     int tagId = 1;