ACR token password enum is incorrect

The [ACR token password enum](https://github.com/Azure/azure-rest-api-specs/blob/69e8e7f15c262df57417fd2b436ac1092b66c588/specification/containerregistry/resource-manager/Microsoft.ContainerRegistry/preview/2021-08-01-preview/containerregistry.json#L4746) is defined as either `password` or `password2`, however, the API returned below when given `password`:

```json
{
"error": {
"code": "InvalidEnumPropertyValue",
"message": "Property value Name is invalid. Expected values are password1, password2."
},
"status": "Failed"
}
```

So probably the Swagger needs to update the enum `password` to `password1`.

Open specification/containerregistry/resource-manager/Microsoft.ContainerRegistry/preview/2021-08-01-preview/containerregistry.json at the linked enum around line 4746. Compare the ACR API error with the enum values there, update the incorrect value, and verify the specification no longer lists the rejected value.

Written by the indexing model from the issue text.