Removign variables we don't use.

Author: ananto-msft

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

@@ -41,16 +41,9 @@ RETRY_INTERVAL=5
 
 # Variables used for azdata cluster creation.
 #
-
-export DOMAIN_SERVICE_ACCOUNT_USERNAME=admin
-export DOMAIN_SERVICE_ACCOUNT_PASSWORD=$password
-
 export CONTROLLER_USERNAME=controlleradmin
 export CONTROLLER_PASSWORD=$password
 
-export MSSQL_SA_PASSWORD=$password
-export KNOX_PASSWORD=$password
-
 export ACCEPT_EULA=yes
 export CLUSTER_NAME=azure-arc-system
 export PV_COUNT="40"