TT#80502 Accept 0777 or 0755 permissions on /var/lib/systemd/coredump

Since the recent change in templates (commit
b95a6ef4ecb9bc3abe44e54506c029569d5a393c) to let systemd-coredump be
able to write to the /var/lib/systemd/coredump directory, it has started
to change the permissions for that pathname 0755 in some circumstances.

This being a symlink, the permissions do not really matter, so we accept
the 0755 permissions matching the target directory (/ngcp-data/coredumps/)
and the 0777 permissions for a default symlink.

Change-Id: Ifc084cb56541e43bd9fa0245464606c1ca992c97

templates/110_filesys-cores.yaml.tt2

@@ -12,7 +12,10 @@ file:
 
   /var/lib/systemd/coredump:
     exists: true
-    mode: "0777"
+    mode:
+      or:
+        - "0777"
+        - "0755"
     owner: root
     group: root
     filetype: symlink