[ACR] Fix helm url with non-regional aka.ms link

[sajayantony]

Description
Update region url to use non-regional aka.ms links

Testing Guide
Before :

az acr helm --help

Group
    az acr helm : Manage helm charts for Azure Container Registries.
        This command group has been deprecated and will be removed in future release. Use 'helm
        v3' instead. For more information go to https://docs.microsoft.com/en-us/azure/container-
        registry/container-registry-helm-repos

After:

az acr helm --help

Group
    az acr helm : Manage helm charts for Azure Container Registries.
        This command group has been deprecated and will be removed in future release. Use 'helm
        v3' instead. For more information go to https://aka.ms/acr/helm

History Notes

[ACR] NON-BREAKING: az acr helm - deprecation url upate

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