Rename isExponentialHistogramFieldName

Author: JonasKunz

x-pack/plugin/analytics/src/main/java/org/elasticsearch/xpack/analytics/mapper/ExponentialHistogramParser.java

@@ -79,8 +79,8 @@ public class ExponentialHistogramParser {
         NEGATIVE_FIELD.getPreferredName()
     );
 
-    public static boolean isExponentialHistogramFieldName(String fieldName) {
-        return ROOT_FIELD_NAMES.contains(fieldName);
+    public static boolean isExponentialHistogramSubFieldName(String subFieldName) {
+        return ROOT_FIELD_NAMES.contains(subFieldName);
     }
 
     /**

x-pack/plugin/analytics/src/main/java/org/elasticsearch/xpack/analytics/mapper/HistogramFieldMapper.java

@@ -326,7 +326,7 @@ public void parse(DocumentParserContext context) throws IOException {
             if (ExponentialHistogramParser.EXPONENTIAL_HISTOGRAM_FEATURE.isEnabled()
                 && coerce()
                 && subParser.currentToken() == XContentParser.Token.FIELD_NAME
-                && ExponentialHistogramParser.isExponentialHistogramFieldName(subParser.currentName())) {
+                && ExponentialHistogramParser.isExponentialHistogramSubFieldName(subParser.currentName())) {
                 ExponentialHistogramParser.ParsedExponentialHistogram parsedExponential = ExponentialHistogramParser.parse(
                     fullPath(),
                     subParser