Remove redundant apt installations;Add package;Lock builder account

packer/config/common.json

@@ -1,7 +1,7 @@
 {
   "build_target": "virt",
   "disable_public_repos": "false",
-  "extra_debs": "open-iscsi",
+  "extra_debs": "nfs-common open-iscsi",
   "extra_repos": "",
   "extra_rpms": "",
   "firstboot_custom_roles_post": "",

packer/ova/packer-node.json

@@ -221,7 +221,7 @@
         }
       ],
       "password": "{{user `password`}}",
-      "shutdown_command": "echo '{{user `ssh_password`}}' | sudo -S -E sh -c '{{user `shutdown_command`}}'",
+      "shutdown_command": "echo '{{user `ssh_password`}}' | sudo -S -E sh -c 'usermod -L {{user `ssh_username`}} && {{user `shutdown_command`}}'",
       "ssh_password": "{{user `ssh_password`}}",
       "ssh_timeout": "4h",
       "ssh_username": "{{user `ssh_username`}}",