tests(packer): define more common cloud init resources.

tests/cloud-init/opensuse-gnome.user-data.yml

@@ -1,21 +1,6 @@
 #cloud-config
 
-packages:
-  - apparmor-profiles
-  - bash-completion
-  - distribution-release
-  - git
-  - go
-  - golang-packaging
-  - htop
-  - make
-  - rpmbuild
-  - rsync
-  - vim
+packages: *core-packages
 
 write_files:
-  # Setup shared directory
-  - path: /etc/fstab
-    append: true
-    content: |
-      0a31bc478ef8e2461a4b1cc10a24cc4 /home/user/Projects/apparmor.d  virtiofs defaults  0  1
+  - *shared-directory  # Setup shared directory