removing duplicated parenthese open (#17975)

removing duplicated parenthese open

docs/java-api/aggs.asciidoc

@@ -47,7 +47,7 @@ SearchResponse sr = node.client().prepareSearch()
         AggregationBuilders.terms("by_country").field("country")
         .subAggregation(AggregationBuilders.dateHistogram("by_year")
             .field("dateOfBirth")
-            .dateHistogramInterval((DateHistogramInterval.YEAR)
+            .dateHistogramInterval(DateHistogramInterval.YEAR)
             .subAggregation(AggregationBuilders.avg("avg_children").field("children"))
         )
     )