az aks get-credentials should automatically convert generated config with azure kubelogin when AAD integrated cluster

**Is your feature request related to a problem? Please describe.**

For AzureAD integrated aks clusters `kubelogin convert-kubeconfig` is required to renew credentials, it's easy to forget/overlook this extra step and have credentials expire making users unable to access the cluster until they do a new `az aks get credentials`.

**Describe the solution you'd like**

It would be a better user experience if `az aks get-credentials` would automatically detect AAD integration and do the conversion step.

**Describe alternatives you've considered**

If that is unreliable having a flag such as `--aad` would also be acceptable.

**Additional context**