Add hub routing preferece in virtual hub properties#17568

zaynchen115 wants to merge 1 commit intoAzure:network-2021-08-01Azure/azure-rest-api-specs:network-2021-08-01from

zaynchen115:zaynchen/routingPrefzaynchen115/azure-rest-api-specs:zaynchen/routingPrefCopy head branch name to clipboard