Restore AggregateExec method order to simplify review

Author: ivancea

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/plan/physical/AggregateExec.java

@@ -136,10 +136,6 @@ public Integer estimatedRowSize() {
         return estimatedRowSize;
     }
 
-    public AggregatorMode getMode() {
-        return mode;
-    }
-
     @Override
     public PhysicalPlan estimateRowSize(State state) {
         state.add(false, aggregates);  // The groupings are contained within the aggregates
@@ -152,6 +148,10 @@ protected AggregateExec withEstimatedSize(int estimatedRowSize) {
         return new AggregateExec(source(), child(), groupings, aggregates, mode, intermediateAttributes, estimatedRowSize);
     }
 
+    public AggregatorMode getMode() {
+        return mode;
+    }
+
     /**
      * Used only for bwc when de-/serializing.
      */