SnapshotException (status_code: 403)

Hi,

I have encountered SnapshotException with status code 403. It turns out that I have a read permission but not write permission for the subscription I was trying to submit my job to. It would be better if the error message was more informative.

This is the current error message
```
raise SnapshotException(get_http_exception_response_string(response))
azureml.exceptions._azureml_exception.SnapshotException: SnapshotException:
Message: {
"status_code": 403,
"url": "..."
}
InnerException None
ErrorResponse
{
"error": {
"message": "{\n \"status_code\": 403,\n \"url\": \"...\"\n}"
}
}
```

I think a better error message would be
```
Please make sure that you have write permission to subscription XYZ.
```

It might also be a good idea to document here what the typical causes for different status codes are.

---
#### Document Details

⚠ *Do not edit this section. It is required for docs.microsoft.com ➟ GitHub issue linking.*

* ID: 9c023d0b-94c0-8b80-3a43-e0d5beb2eefb
* Version Independent ID: 22714d0e-0f49-7264-5329-7c7b3e163d2d
* Content: [azureml.exceptions.SnapshotException class - Azure Machine Learning Python](https://docs.microsoft.com/en-us/python/api/azureml-core/azureml.exceptions.snapshotexception?view=azure-ml-py)
* Content Source: [AzureML-Docset/stable/docs-ref-autogen/azureml-core/azureml.exceptions.SnapshotException.yml](https://github.com/MicrosoftDocs/MachineLearning-Python-pr/blob/live/AzureML-Docset/stable/docs-ref-autogen/azureml-core/azureml.exceptions.SnapshotException.yml)
* Service: **machine-learning**
* Sub-service: **core**
* GitHub Login: @debfro
* Microsoft Alias: **debfro**

L’issue identifie azureml.exceptions.SnapshotException et la source de référence de SnapshotException dans AzureML-Docset/stable/docs-ref-autogen/azureml-core/azureml.exceptions.SnapshotException.yml ; commencez par retracer la manière dont la réponse 403 est transmise. Le travail est terminé lorsqu’une erreur d’autorisation plus informative est fournie, que les causes typiques des codes d’état pertinents sont documentées et que le cas 403 est vérifié.

Rédigé par le modèle d'indexation à partir du texte de l'issue.