Flat object field should delegate to keyword field for most query types

Signed-off-by: kkewwei <[email protected]>

Author: kkewwei

server/src/main/java/org/opensearch/common/xcontent/JsonToStringXContentParser.java

@@ -24,6 +24,11 @@
 import java.nio.CharBuffer;
 import java.util.ArrayList;
 
+import static org.opensearch.index.mapper.FlatObjectFieldMapper.DOT_SYMBOL;
+import static org.opensearch.index.mapper.FlatObjectFieldMapper.EQUAL_SYMBOL;
+import static org.opensearch.index.mapper.FlatObjectFieldMapper.VALUE_AND_PATH_SUFFIX;
+import static org.opensearch.index.mapper.FlatObjectFieldMapper.VALUE_SUFFIX;
+
 /**
  * JsonToStringParser is the main parser class to transform JSON into stringFields in a XContentParser
  * returns XContentParser with one parent field and subfields
@@ -44,11 +49,6 @@ public class JsonToStringXContentParser extends AbstractXContentParser {
 
     private DeprecationHandler deprecationHandler;
 
-    private static final String VALUE_AND_PATH_SUFFIX = "._valueAndPath";
-    private static final String VALUE_SUFFIX = "._value";
-    private static final String DOT_SYMBOL = ".";
-    private static final String EQUAL_SYMBOL = "=";
-
     public JsonToStringXContentParser(
         NamedXContentRegistry xContentRegistry,
         DeprecationHandler deprecationHandler,