Add e2e test for conv+bn (#27348)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/27348
att
Test Plan:
python test/test_quantization.py
Imported from OSS
Differential Revision: D18182920
fbshipit-source-id: 40edc4d85903f979cd4755d6785d2842faa4d566
