When you create an newUploadPhotoRequest, that method will implicitly add some parameters to the Request object that's returned. When you call setParameter, you're replacing those implicit parameters with your own, which causes the request to be missing some required params.
What you should do instead is:
Request request = Request.newUploadPhotoRequest(Session.getActiveSession(), BitmapFactory.decodeResource(_context.getResources(), R.drawable.default_image), uploadPhotoRequestCallback);
Bundle parameters = request.getParameters(); // <-- THIS IS IMPORTANT
parameters.putString(...);
// add more params here
request.setParameters(parameters);
request.executeAsync();