Azure Dabatase for MySQL Flexible Server keeps busy (status "Starting") and does not accept any az-cli command

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

## Describe the bug

**Command Name**
`az mysql flexible-server start`

**Errors:**
```
AzureResponseError: Failed to connect to MSI. Please make sure MSI is configured correctly.
Get Token request returned:
```

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

- Stopped server through Portal
- Started server also through Portal
- (server kept "Starting" for hours)
- Tried to stop, start, restart using az-cli: `az mysql flexible-server start --name {} --resource-group {}`

## Expected Behavior

Stop, start or restart the server was expected.

## Environment Summary
```
Linux-4.15.0-1102-azure-x86_64-with-debian-10.2 (Cloud Shell)
Python 3.6.10
Installer: DEB

azure-cli 2.16.0

Extensions:
ai-examples 0.2.5

```
## Additional Context

Additional error message when trying to stop the instance:
```
az mysql flexible-server stop --name {} --resource-group {}
Command group 'mysql flexible-server' is in preview. It may be changed/removed in a future release.
Deployment failed. Correlation ID: 470cb646-1ceb-4129-a044-20ca3375ddb2. Operation Stop failed, because server {} is busy with other operations.
```