Fix centroids equality tests in TDigestState#equals

core/src/main/java/org/elasticsearch/search/aggregations/metrics/percentiles/tdigest/InternalTDigestPercentileRanks.java

@@ -116,9 +116,4 @@ public class InternalTDigestPercentileRanks extends AbstractInternalTDigestPerce
             throw new UnsupportedOperationException();
         }
     }
-
-    @Override
-    protected boolean doEquals(Object obj) {
-        return super.doEquals(obj);
-    }
 }

core/src/main/java/org/elasticsearch/search/aggregations/metrics/percentiles/tdigest/TDigestState.java

@@ -72,7 +72,7 @@ public class TDigestState extends AVLTreeDigest {
             return false;
         }
         Iterator<? extends Centroid> thisCentroids = centroids().iterator();
-        Iterator<? extends Centroid> thatCentroids = centroids().iterator();
+        Iterator<? extends Centroid> thatCentroids = that.centroids().iterator();
         while (thisCentroids.hasNext()) {
             if (thatCentroids.hasNext() == false) {
                 return false;