fix(pg-cdc): fix AWS RDS endpoint behind a privatelink (#15348) (#15367)

Co-authored-by: StrikeW <[email protected]>

Author: kwannoel

java/connector-node/risingwave-connector-service/src/main/java/com/risingwave/connector/source/common/PostgresValidator.java

@@ -42,7 +42,7 @@ public class PostgresValidator extends DatabaseValidator implements AutoCloseabl
 
     private final boolean pubAutoCreate;
 
-    private static final String AWS_RDS_HOST = "rds.amazonaws.com";
+    private static final String AWS_RDS_HOST = "amazonaws.com";
     private final boolean isAwsRds;
 
     // Whether the properties to validate is shared by multiple tables.