Fix usage of "|" for tests

With the more recent versions of ansible, we should now use
"is" instead of the "|" sign for the tests.

This should fix it.

Change-Id: Id39023e9801f2bf114fbb02e89e13e1452e6b928

tests/test-create-btrfs-dev.yml

@@ -40,7 +40,7 @@
         fstype: btrfs
         dev: /var/lib/sparse-file.img
       when:
-        - sparse_file | changed
+        - sparse_file  is changed
   vars:
     btrfs_package:
       apt: "btrfs-tools"

tests/test-create-nfs-dev.yml

@@ -70,7 +70,7 @@
         enabled: "yes"
         state: "restarted"
       when:
-        - nfs_exportfs | changed
+        - nfs_exportfs  is changed
 
     - name: Export NFS
       command: exportfs -rav

tests/test-create-swap-dev.yml

@@ -29,4 +29,4 @@
       command: mkswap /var/lib/test-swap.img
       failed_when: false
       when:
-        - create_swap | changed
+        - create_swap  is changed