[fix](Nereids) fix fold constant of time acquired functions

fe/fe-core/src/main/java/org/apache/doris/nereids/parser/LogicalPlanBuilder.java

@@ -2387,37 +2387,37 @@ public Expression visitArithmeticBinary(ArithmeticBinaryContext ctx) {
 
     @Override
     public Expression visitCurrentDate(DorisParser.CurrentDateContext ctx) {
-        return new CurrentDate().alias("CURRENT_DATE");
+        return new CurrentDate();
     }
 
     @Override
     public Expression visitCurrentTime(DorisParser.CurrentTimeContext ctx) {
-        return new CurrentTime().alias("CURRENT_TIME");
+        return new CurrentTime();
     }
 
     @Override
     public Expression visitCurrentTimestamp(DorisParser.CurrentTimestampContext ctx) {
-        return new Now().alias("CURRENT_TIMESTAMP");
+        return new Now();
     }
 
     @Override
     public Expression visitLocalTime(DorisParser.LocalTimeContext ctx) {
-        return new CurrentTime().alias("LOCALTIME");
+        return new CurrentTime();
     }
 
     @Override
     public Expression visitLocalTimestamp(DorisParser.LocalTimestampContext ctx) {
-        return new Now().alias("LOCALTIMESTAMP");
+        return new Now();
     }
 
     @Override
     public Expression visitCurrentUser(DorisParser.CurrentUserContext ctx) {
-        return new CurrentUser().alias("CURRENT_USER");
+        return new CurrentUser();
     }
 
     @Override
     public Expression visitSessionUser(DorisParser.SessionUserContext ctx) {
-        return new SessionUser().alias("SESSION_USER");
+        return new SessionUser();
     }
 
     @Override

regression-test/suites/nereids_p0/expression/fold_constant/fold_constant_date_arithmatic.groovy

@@ -0,0 +1,32 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+suite("fold_constant_date_arithmatic") {
+    def db = "fold_constant_date_arithmatic"
+    sql "create database if not exists ${db}"
+
+    sql "set enable_nereids_planner=true"
+    sql "set enable_fallback_to_original_planner=false"
+    sql "set enable_fold_constant_by_be=false"
+
+    testFoldConst("select substr(now(), 1, 10);")
+    testFoldConst("select substr(now(3), 1, 10);")
+    testFoldConst("select substr(curdate(), 1, 10);")
+    testFoldConst("select substr(current_date(), 1, 10);")
+    testFoldConst("select substr(current_timestamp(), 1, 10);")
+    testFoldConst("select substr(current_timestamp(3), 1, 10);")
+}