fix flakytest when tests.locale=tr (#1827) (#1839)

Signed-off-by: Peng Huo <penghuo@gmail.com>
(cherry picked from commit 4178c03)

Co-authored-by: Peng Huo <penghuo@gmail.com>

protocol/src/main/java/org/opensearch/sql/protocol/response/QueryResult.java

@@ -9,6 +9,7 @@
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.LinkedHashMap;
+import java.util.Locale;
 import java.util.Map;
 import lombok.Getter;
 import lombok.RequiredArgsConstructor;
@@ -58,7 +59,7 @@ public Map<String, String> columnNameTypes() {
     Map<String, String> colNameTypes = new LinkedHashMap<>();
     schema.getColumns().forEach(column -> colNameTypes.put(
         getColumnName(column),
-        column.getExprType().typeName().toLowerCase()));
+        column.getExprType().typeName().toLowerCase(Locale.ROOT)));
     return colNameTypes;
   }