Allow the usage of Ephemeral OS Disk with multiple VM SKUs

[naioja]

Is your feature request related to a problem? Please describe. I would like to use VM SKUs as AKS nodepools that support Ephemeral Disk but the cache size is not larger than 130GiB. One example would be the VM SKU Standard_DS2_v2 that has 86 GiB and documented here : https://learn.microsoft.com/en-us/azure/aks/cluster-configuration#ephemeral-os

Describe the solution you'd like The ability to use a broader less expensive VM SKU variety that have over 30 GiB of cache storage.