az connectedk8s connect fails if helm 3.7.0 is installed

## Describe the bug

**Command Name**

`az connectedk8s connect
(Extension Name: connectedk8s. Version: 1.1.10.)`

Impossible to onboard a kubernetes cluster to Azure using command `az connectedk8s connect`

**Errors:**
```
Unable to pull helm chart from the registry 'mcr.microsoft.com/azurearck8s/batch1/stable/azure-arc-k8sagents:1.4.0': Error: unknown command "chart" for "helm"
Run 'helm --help' for usage.

```

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

- with helm version 3.7.0 installed
- `az connectedk8s connect --name {} --resource-group {} --location {} --kube-config {}`

The issue seems to be related to a breaking change in helm 3.7:
- `helm chart pull` has been replaced with `helm pull` (source: https://github.com/helm/helm/releases/tag/v3.7.0)

``

## Expected Behavior
Should successfully onboard the kubernetes cluster to azure.
The same command used with helm 3.6.3 runs successfully.

## Environment Summary
```
Linux-5.8.0-1041-azure-x86_64-with-debian-bullseye-sid, Ubuntu 20.04.3 LTS
Python 3.6.10
Installer: DEB

azure-cli 2.28.0

Extensions:
k8s-extension 0.7.1
connectedk8s 1.1.10
customlocation 0.1.2
k8s-configuration 1.1.0

```
## Additional Context