Dropwizard apply label mapper to snapshot metrics (#1266)

Also allowed to override getHelpMessage

---------

Signed-off-by: Kacper Filutowski <kacper.filutowski@tomtom.com>
Signed-off-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>
Co-authored-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>

Author: KacperFilutowski-TomTom

prometheus-metrics-instrumentation-dropwizard/src/main/java/io/prometheus/metrics/instrumentation/dropwizard/DropwizardExports.java

@@ -169,8 +169,10 @@ MetricSnapshot fromSnapshotAndCount(
             .quantile(0.999, snapshot.get999thPercentile() * factor)
             .build();
 
+    String name =
+        labelMapper.isPresent() ? labelMapper.get().getName(dropwizardName) : dropwizardName;
     MetricMetadata metadata =
-        new MetricMetadata(PrometheusNaming.sanitizeMetricName(dropwizardName), helpMessage);
+        new MetricMetadata(PrometheusNaming.sanitizeMetricName(name), helpMessage);
     SummarySnapshot.SummaryDataPointSnapshot.Builder dataPointBuilder =
         SummarySnapshot.SummaryDataPointSnapshot.builder().quantiles(quantiles).count(count);
     labelMapper.ifPresent(

prometheus-metrics-instrumentation-dropwizard5/src/main/java/io/prometheus/metrics/instrumentation/dropwizard5/DropwizardExports.java

@@ -169,8 +169,10 @@ MetricSnapshot fromSnapshotAndCount(
             .quantile(0.999, snapshot.get999thPercentile() * factor)
             .build();
 
+    String name =
+        labelMapper.isPresent() ? labelMapper.get().getName(dropwizardName) : dropwizardName;
     MetricMetadata metadata =
-        new MetricMetadata(PrometheusNaming.sanitizeMetricName(dropwizardName), helpMessage);
+        new MetricMetadata(PrometheusNaming.sanitizeMetricName(name), helpMessage);
     SummarySnapshot.SummaryDataPointSnapshot.Builder dataPointBuilder =
         SummarySnapshot.SummaryDataPointSnapshot.builder().quantiles(quantiles).count(count);
     labelMapper.ifPresent(