quant BN tests: remove qint32 (#37832)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/37832
These tests were flaky and qint32 support is not a priority at
the moment, turning it off to improve test quality.
Test Plan:
```
python test/test_quantization.py TestQuantizedOps.test_batch_norm2d
python test/test_quantization.py TestQuantizedOps.test_batch_norm2d_relu
python test/test_quantization.py TestQuantizedOps.test_batch_norm3d
```
Imported from OSS
Differential Revision: D21404980
fbshipit-source-id: 04f4308bc5d6e1a278c60985971d03c10a851915
