Move away from ConstantFill (#16214)
Summary:
Prerequisite of https://github.com/onnx/onnx/pull/1434
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16214
Reviewed By: BIT-silence
Differential Revision: D13755116
Pulled By: houseroad
fbshipit-source-id: a46be8d7df959b5ede93e1f9c911a9a9326e6879
