Bug Fix: Customized Serialization.
Bug Fix: Customized Serialization.

(By Jin Li) Fix a bug related to customized serialization. I would like to check-in this fix to allow Yuxiao/Lei to move forward.
Bruno is working on additional UnitTest to cover scenario of Serialization by BinaryFormatter, Prajna,
and deserialize by a common API. When that is done, I will add additional UnitTest to cover customized serialization/deserialization.

hongzhili/Prajna,BrunoBozza/Prajna,jinlmsft/Prajna,MSRCCS/Prajna,leizhangcn/Prajna,MSRCCS/Prajna,jinlmsft/Prajna,hongzhili/Prajna,jinlmsft/Prajna,MSRCCS/Prajna,leizhangcn/Prajna,jinlmsft/Prajna,BrunoBozza/Prajna,MSRCCS/Prajna,BrunoBozza/Prajna,YuxiaoHu/Prajna,BrunoBozza/Prajna,YuxiaoHu/Prajna