update in aks backup support matrix

Author: rajats22

articles/backup/azure-kubernetes-service-cluster-backup-support-matrix.md

@@ -56,7 +56,7 @@ You can use [Azure Backup](./backup-overview.md) to help protect Azure Kubernete
 
 - The blob container provided as input during installation of the backup extension should be in the same region and subscription as that of the AKS cluster. Only blob containers in a General-purpose V2 Storage Account are supported and Premium Storage Account aren't supported.   
 
-- The Backup vault and the AKS cluster should be in the same region and subscription.
+- Backup Vault and the AKS cluster should be located in the same region. However, they can reside in different subscriptions as long as they are within the same tenant.
 
 - Azure Backup for AKS provides both Operational Tier (Snapshot) and Vault Tier backup. Multiple backups per day can be stored in Operational Tier, with only one backup per day to be stored in the Vault as per the retention policy defined.