az aks get-credentials does not merge the kubeconfig when it was converted with azure kubelogin

## Describe the bug
When the kubeconfig was converted with the azure kubelogin tool by `kubelogin convert-kubeconfig`, the next aks credential downloads will not be correctly merged into the kubeconfig file.
The `az aks get-credentials` command will simply return (cluster name redacted)
```bash
Merged "CLUSTER_NAME" as current context in C
```

The kubeconfig file will not be edited by the command. I needed to manually add the new context, clusters and user to the file.

**Command Name**
`az aks get-credentials`

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

- `kubelogin convert-kubeconfig`
- `az aks get-credentials --resource-group {} --name {}`
- `Merged "CLUSTER_NAME" as current context in C`

## Expected Behavior
The kubernetes context will be merged into the existing kubeconfig
## Environment Summary
```
Windows-10-10.0.19044-SP0
Python 3.10.4
Installer: MSI

azure-cli 2.37.0 *

Extensions:
managementpartner 0.1.3

Dependencies:
msal 1.18.0b1
azure-mgmt-resource 21.1.0b1
```
## Additional Context