resurrect single quantization op test (#41476)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/41476
deleted this test by default, re-adding it in its own file to make it
more explicit
Test Plan: ran the test
Reviewed By: yinghai
Differential Revision: D22550217
fbshipit-source-id: 758e279b2bab3b23452a3d0ce75fb366f7afb7be
