Broken exercise content in https://docs.microsoft.com/en-us/learn/modules/protect-virtual-machines-with-azure-backup/4-exercise-back-up-azure-virtual-machine

### **This is autogenerated. Please review and update as needed.**

## Describe the bug

**Command Name**
`az backup protection enable-for-vm`

**Errors:**
```
The Resource 'Microsoft.RecoveryServices/vaults/azure-backup' under resource group 'vmbackups' was not found. For more details please go to https://aka.ms/ARMResourceNotFoundFix
```
Before launching 'az backup protection' in the UI the 'choose backup policy' always displayed 'Loading...'.

## To Reproduce:
Did all the steps in https://docs.microsoft.com/en-us/learn/modules/protect-virtual-machines-with-azure-backup/4-exercise-back-up-azure-virtual-machine

RGROUP=$(az group create --name vmbackups --location westus2 --output tsv --query name)
az network vnet create \
--resource-group $RGROUP \
--name NorthwindInternal \
--address-prefix 10.0.0.0/16 \
--subnet-name NorthwindInternal1 \
--subnet-prefix 10.0.0.0/24

az vm create \
--resource-group $RGROUP \
--name NW-APP01 \
--size Standard_DS1_v2 \
--vnet-name NorthwindInternal \
--subnet NorthwindInternal1 \
--image Win2016Datacenter \
--admin-username admin123 \
--no-wait \
--admin-password

az backup protection enable-for-vm \
--resource-group vmbackups \
--vault-name azure-backup \
--vm NW-APP01 \
--policy-name DefaultPolicy

## Expected Behavior

## Environment Summary
```
Linux-4.15.0-1110-azure-x86_64-with-debian-10.2 (Cloud Shell)
Python 3.6.10
Installer: DEB

azure-cli 2.20.0

Extensions:
ai-examples 0.2.5

```
## Additional Context