quant: clean up normalization channels_last handling (#37802)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/37802
* adds test coverage for channels_last input format for quantized normalization ops
* fixes quantized group_norm and instance_norm to always return contiguous tensors
Test Plan:
```
python test/test_quantization.py TestQuantizedOps.test_group_norm
python test/test_quantization.py TestQuantizedOps.test_qlayer_norm
python test/test_quantization.py TestQuantizedOps.test_instance_norm
```
Imported from OSS
Differential Revision: D21395196
fbshipit-source-id: df55e842fe93ae594a336f1b115faea9ba3c88c1
