Does not work for reading value for untyped property with odata.type annotated

[xuzhg]

If we post a request using

{
"name": "sam",
"gender": "Male",
"data@odata.type":"#UntypedApp.Models.Gender",
"data": "Male"
}
There's a type annotation for 'data'.

Expected behavior
Shoudl read it as 'Gender.Male' for 'Data' property.

** Actual behavior**
It's failed.

It's also failing if we specify a @odata.type for a single resource for 'Data'.