[sdk-metrics] Refactor exemplar offer duplicated code into helper methods inside MetricPoint (#5399)

Author: CodeBlanch

src/OpenTelemetry/Metrics/AggregatorStore.cs

@@ -996,7 +996,7 @@ private void UpdateLongCustomTags(long value, ReadOnlySpan<KeyValuePair<string,
             if (this.IsExemplarEnabled())
             {
                 var shouldSample = this.exemplarFilter.ShouldSample(value, tags);
-                this.metricPoints[index].UpdateWithExemplar(value, tags: tags, shouldSample);
+                this.metricPoints[index].UpdateWithExemplar(value, tags, shouldSample);
             }
             else
             {
@@ -1084,7 +1084,7 @@ private void UpdateDoubleCustomTags(double value, ReadOnlySpan<KeyValuePair<stri
             if (this.IsExemplarEnabled())
             {
                 var shouldSample = this.exemplarFilter.ShouldSample(value, tags);
-                this.metricPoints[index].UpdateWithExemplar(value, tags: tags, shouldSample);
+                this.metricPoints[index].UpdateWithExemplar(value, tags, shouldSample);
             }
             else
             {