[Fix] Only datetime and datetimev2 types can use current_timestamp as column default value (#31395)

for this kind of sql:

create table test_default10(
  a int, 
  b varchar(100) default current_timestamp
)
distributed by hash(a)
properties('replication_num'="1");

add check:
 Types other than DATETIME and DATETIMEV2 cannot use current_timestamp as the default value

fe/fe-core/src/main/java/org/apache/doris/analysis/ColumnDef.java

@@ -542,6 +542,16 @@ public class ColumnDef {
             default:
                 throw new AnalysisException("Unsupported type: " + type);
         }
+        if (null != defaultValueExprDef && defaultValueExprDef.getExprName().equals("now")) {
+            switch (primitiveType) {
+                case DATETIME:
+                case DATETIMEV2:
+                    break;
+                default:
+                    throw new AnalysisException("Types other than DATETIME and DATETIMEV2 "
+                            + "cannot use current_timestamp as the default value");
+            }
+        }
     }
 
     public String toSql() {