Make role multiplatform

- On debian 11 strongswan daemon has different name
- Make config file backups when overwriting
- Add closeaction configuration option
- More metadata fixes
- Change tests to run standalone

Change-Id: I04474cb4601060059c4e603560d1873ad6598a77
diff --git a/vars/Ubuntu_18.04.yml b/vars/Ubuntu_18.04.yml
new file mode 100644
index 0000000..692e778
--- /dev/null
+++ b/vars/Ubuntu_18.04.yml
@@ -0,0 +1,11 @@
+---
+# strongswan vars/Ubuntu_18.04.yml
+#
+# SPDX-FileCopyrightText: © 2022 Open Networking Foundation <support@opennetworking.org>
+# SPDX-License-Identifier: Apache-2.0
+#
+# NOTE: Only put platform/OS-specific variables in this file.
+# Put all other variables in the 'defaults/main.yml' file.
+
+strongswan_package: strongswan
+strongswan_service: strongswan