[ComponentBased.Port][Non-ACR] Fix XML serialization by adding writer.Flush() call

Add missing writer.Flush() to ensure XML data is properly
written to stream during serialization. This prevents
"Unexpected end of file" deserialization errors.

Signed-off-by: Changgyu Choi <[email protected]>

Author: upple

src/Tizen.Applications.ComponentBased.Port/Tizen.Applications.ComponentBased.Port/ComponentPort.cs

@@ -371,6 +371,7 @@ private Parcel ToParcel(object envelope)
                         var serializer = new DataContractSerializer(envelope.GetType());
                         serializer.WriteObject(writer, envelope);
                         writer.WriteEndElement();
+                        writer.Flush();
 
                         parcel = new Parcel();
                         parcel.UnMarshall(stream.ToArray());