az monitor activity-log alert list

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

## Describe the bug

running
az monitor activity-log alert list

some results fine, then the following error

ERROR: The command failed with an unexpected error. Here is the traceback:
ERROR: Unable to deserialize to object: type, AttributeError: 'str' object has no attribute 'get'
Traceback (most recent call last):
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\msrest/serialization.py", line 1428, in _deserialize
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\msrest/serialization.py", line 1172, in rest_key_extractor
AttributeError: 'str' object has no attribute 'get'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\knack/cli.py", line 233, in invoke
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 660, in execute
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 723, in _run_jobs_serially
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 715, in _run_job
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/command_modules/monitor/_exception_handler.py", line 23, in exception_handler
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/cli/core/commands/__init__.py", line 707, in _run_job
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/core/paging.py", line 129, in __next__
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/core/paging.py", line 76, in __next__
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\azure/mgmt/monitor/v2017_04_01/operations/_activity_log_alerts_operations.py", line 363, in get_next
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\msrest/serialization.py", line 1368, in __call__
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\msrest/serialization.py", line 1446, in _deserialize
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\msrest/exceptions.py", line 51, in raise_with_traceback
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\msrest/serialization.py", line 1428, in _deserialize
File "D:\a\1\s\build_scripts\windows\artifacts\cli\Lib\site-packages\msrest/serialization.py", line 1172, in rest_key_extractor
msrest.exceptions.DeserializationError: Unable to deserialize to object: type, AttributeError: 'str' object has no attribute 'get'
**Command Name**
`az monitor activity-log alert list`

**Errors:**

## 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 monitor activity-log alert list`

## Expected Behavior

## Environment Summary
```
Windows-10-10.0.19041-SP0
Python 3.6.8
Installer: MSI

azure-cli 2.21.0

Extensions:
log-analytics-solution 0.1.1
resource-graph 1.1.0

```
## Additional Context