[fix](planner) fix current_timestamp param type mismatch when doing stream load (#23092)

FileLoadScanNode did not analyze the default value expr, result in target param type int32 become int8 as the original IntLiteral type.

fe/fe-core/src/main/java/org/apache/doris/planner/external/FileScanNode.java

@@ -175,6 +175,7 @@ public abstract class FileScanNode extends ExternalScanNode {
             if (column.getDefaultValue() != null) {
                 if (column.getDefaultValueExprDef() != null) {
                     expr = column.getDefaultValueExpr();
+                    expr.analyze(analyzer);
                 } else {
                     expr = new StringLiteral(column.getDefaultValue());
                 }

regression-test/data/correctness_p0/test_current_timestamp.out

@@ -12,28 +12,28 @@
 4
 
 -- !stream_load_csv1 --
-4
+5
 
 -- !stream_load_csv2 --
-4
+5
 
 -- !stream_load_csv3 --
-4
+5
 
 -- !stream_load_csv4 --
-4
+5
 
 -- !stream_load_json1 --
-2
+3
 
 -- !stream_load_json2 --
-2
+3
 
 -- !stream_load_json3 --
-2
+3
 
 -- !stream_load_json4 --
-2
+3
 
 -- !stream_load_json5 --
 9	apache

regression-test/data/correctness_p0/test_current_timestamp_streamload.csv

@@ -1,4 +1,5 @@
 5,ee
 6,ff
 7,gg
-8,hh
+8,hh
+9,