[quant][onnx] Support conversion of quantized sigmoid operator from pytorch to caffe2 (#34629)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34629
Add support for sigmoid in the conversion flow through onnx
Test Plan:
python test/onnx/test_pytorch_onnx_caffe2_quantized.py TestQuantizedOps.test_quantized_sigmoid
python test/onnx/test_pytorch_onnx_caffe2_quantized.py TestQuantizedOps.test_small_model
Imported from OSS
Differential Revision: D20433680
fbshipit-source-id: 95943e14637d294122e4d102c5c19c06d27064c6
