Add more regions in bootstrapper script

Author: shul-msft

samples/features/azure-arc/deployment/kubeadm/ubuntu-single-node-vm/setup-controller.sh

@@ -62,7 +62,7 @@ fi
 
 if [ -z "$ARC_DC_REGION" ]
 then
-    read -p "Enter a region for the new Azure Arc Data Controller (eastus or eastus2): " dc_region
+    read -p "Enter a region for the new Azure Arc Data Controller (eastus, eastus2, centralus, westus2, westeurope or southeastasia): " dc_region
     echo
     export ARC_DC_REGION=$dc_region
 fi