Summary:

Per channel weights observer in conv transpose is not supported yet.  Adding an
error message which fails instantly instead of making the user wait until after
calibration/training finishes.

Test Plan:

```
python test/test_quantization.py TestPostTrainingStatic.test_convtranspose_per_channel_fails_early
python test/test_quantization.py TestQuantizeFx.test_convtranspose_per_channel_fails_early
```

Reviewers:

Subscribers:

Tasks:

Tags:

[ghstack-poisoned]

…l weight"

Summary:

Per channel weights observer in conv transpose is not supported yet.  Adding an
error message which fails instantly instead of making the user wait until after
calibration/training finishes.

Test Plan:

```
python test/test_quantization.py TestPostTrainingStatic.test_convtranspose_per_channel_fails_early
python test/test_quantization.py TestQuantizeFx.test_convtranspose_per_channel_fails_early
```

Reviewers:

Subscribers:

Tasks:

Tags:

Differential Revision: [D25717151](https://our.internmc.facebook.com/intern/diff/D25717151)

[ghstack-poisoned]