Django Rest Swagger 2 not parsing Serializer FieldField correctly

Let us say I have the following serializer:

class FileUploadSerializer(serializers.Serializer):
     file = serializers.FileField(max_length=100)

My view looks like this:

class FileUploadView(generics.CreateGenericAPIView):
    serializer_class = serializers.FileUploadSerializer
    parser_classes = (parsers.FileUploadParser,)

    def post(self, request):
        # do something here

I expected the swagger UI to generate a file upload button that you can click to choose a file from the file system. Instead, I was asked to input a JSON data:

In the older version of the Django Swagger, I can just specify the parameter type as file in the YAML docstrings. However, I am using Django Swagger 2+ where YAML docstrings are no longer supported.