Ensure public access is disabled for Azure Managed Disk

Allowing unrestricted, public access to cloud services could open an application up to external attack. Disallowing this access is typically considered best practice.

In Azure Console -

1. In Azure portal, navigate to managed disk.
2. Click on networking, and select Private endpoint.

In Terraform -

1. In the azurerm_managed_disk resource, set 'network_access_policy' attribute to 'AllowPrivate'.

References:
https://learn.microsoft.com/en-us/azure/virtual-machines/managed-disks-overview
https://learn.microsoft.com/en-us/azure/private-link/private-link-overview
https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/managed_disk#network_access_policy