Here 6 I uploaded all the files needed to reproduce the case.

First we run python trace_model.py to make simple torchscript version of weights.
Then test results on image with python demo.py.

After that uncomment the following lines in trace_model.py:
# backend = "qnnpack"
# model.qconfig = torch.quantization.get_default_qconfig(backend)
# torch.backends.quantized.engine = backend
# model = torch.quantization.prepare(model, inplace=False)
# model = torch.quantization.convert(model, inplace=False)

and repeat steps 1,2 again;