Remove constant propagation expect files (#16348)
Summary:
Remove constant prop expect files, and express graph conditions via python bindings.
First diff in larger effort to remove expect files
Pull Request resolved: https://github.com/pytorch/pytorch/pull/16348
Differential Revision: D13906929
Pulled By: eellison
fbshipit-source-id: 7963caa3ccbc7bfc0006a160c952aa173d1ce633
