Merge pull request #1 from chianw/chianw-patch-1

Corrected the command for Grant permission on storage account

Author: chianw

articles/backup/azure-kubernetes-service-cluster-manage-backups.md

@@ -120,7 +120,7 @@ To stop the Backup Extension install operation, use the following command:
 To provide *Storage Account Contributor Permission* to the Extension Identity on storage account, run the following command:
 
    ```azurecli-interactive
-   az role assignment create --assignee-object-id $(az k8s-extension show --name azure-aks-backup --cluster-name <aksclustername> --resource-group <aksclusterrg> --cluster-type managedClusters --query identity.principalId --output tsv) --role 'Storage Blob Data Contributor' --scope /subscriptions/<subscriptionid>/resourceGroups/<storageaccountrg>/providers/Microsoft.Storage/storageAccounts/<storageaccountname> 
+   az role assignment create --assignee-object-id $(az k8s-extension show --name azure-aks-backup --cluster-name <aksclustername> --resource-group <aksclusterrg> --cluster-type managedClusters --query aksAssignedIdentity.principalId --output tsv) --role 'Storage Blob Data Contributor' --scope /subscriptions/<subscriptionid>/resourceGroups/<storageaccountrg>/providers/Microsoft.Storage/storageAccounts/<storageaccountname> 
    ```