Proto precision (#482)

* upgrade version

* add precision to messages

Author: BrandonArp

pom.xml

@@ -90,7 +90,7 @@
     <logback.steno.version>2.1.2</logback.steno.version>
     <log4j.over.slf4j.version>2.0.16</log4j.over.slf4j.version>
     <metrics.aggregator.protocol.prometheus.version>1.1.0</metrics.aggregator.protocol.prometheus.version>
-    <metrics.aggregator.protocol.version>1.1.0</metrics.aggregator.protocol.version>
+    <metrics.aggregator.protocol.version>1.2.1</metrics.aggregator.protocol.version>
     <metrics.client.version>0.13.0</metrics.client.version>
     <metrics.client.http.version>0.13.1</metrics.client.http.version>
     <metrics.client.incubator.version>0.13.0</metrics.client.incubator.version>

src/main/java/com/arpnetworking/tsdcore/model/PeriodicDataToProtoConverter.java

@@ -143,6 +143,9 @@ private static ByteString serializeSupportingData(final AggregatedData datum) {
             }
             builder.setUnit(unit);
 
+            // Need to add 1 since 0 is the default value and indicates no precision was set.
+            builder.setPrecision(histogram.getPrecision() + 1);
+
             for (final Map.Entry<Double, Long> entry : histogram.getValues()) {
                 builder.addEntriesBuilder()
                         .setBucket(entry.getKey())