all field mapper should be "included in root object"

modules/elasticsearch/src/main/java/org/elasticsearch/index/mapper/internal/AllFieldMapper.java

@@ -162,7 +162,7 @@ public class AllFieldMapper extends AbstractFieldMapper<Void> implements Interna
     }
 
     @Override public boolean includeInObject() {
-        return false;
+        return true;
     }
 
     @Override protected Fieldable parseCreateField(ParseContext context) throws IOException {