az container create failed, but network profile was created.


### **This is autogenerated. Please review and update as needed.**

## Describe the bug

**Command Name**
`az container create`

**Errors:**
```
'NetworkProfile' object has no attribute 'result'
Traceback (most recent call last):
python3.6/site-packages/knack/cli.py, ln 233, in invoke
cmd_result = self.invocation.execute(args)
cli/core/commands/__init__.py, ln 659, in execute
raise ex
cli/core/commands/__init__.py, ln 722, in _run_jobs_serially
results.append(self._run_job(expanded_arg, cmd_copy))
...
cli/command_modules/container/custom.py, ln 348, in _get_vnet_network_profile
network_profile = ncf.network_profiles.create_or_update(resource_group_name, default_network_profile_name, network_profile).result()
AttributeError: 'NetworkProfile' object has no attribute 'result'
```

## To Reproduce:
Steps to reproduce the behavior. Note that argument values have been redacted, as they may contain sensitive information.

- _Put any pre-requisite steps here..._
- `az container create --name {} --resource-group {} --image {} --vnet {} --subnet {}`

## Expected Behavior

## Environment Summary
```
Linux-5.4.0-1036-azure-x86_64-with-debian-buster-sid
Python 3.6.10
Installer: DEB

azure-cli 2.18.0

```
## Additional Context