apertis-update-manager-automount: Fix unknown key setup (again)

The bundle generation with an unknown key doesn't display correctly.
Move bundle generation to `pre-conditions`.
Add `cryptsetup` package installation

Signed-off-by: Frédéric Danis <frederic.danis@collabora.com>

test-cases/apertis-update-manager-automount.yaml

@@ -19,8 +19,12 @@ metadata:
     - "A second Fat32 USB flash drive, preloaded with the encrypted update bundle at the root of the disk"
     - "The latest encrypted static update file can be downloaded at the same location than the target image. It has the same basename, and a '.delta.enc' extension"
     - "The static encrypted update file should be copied to the second flash drive using the name 'static-update.bundle.enc'."
-    - "A third Fat32 USB flash drive, preloaded with the encrypted update bundle with unknown key at the root of the disk"
-    - "This can be generated from the encrypted update bundle using one of the key used for encryption (saved to key0.key) and the following commands:"
+    - "A third Fat32 USB flash drive, which will contain the encrypted update bundle with unknown key at the root of the disk"
+    - "A PC must be connected to DUT serial port"
+
+  pre-conditions:
+    - "The encrypted update bundle with unknown key can be generated from the encrypted update bundle using one of the key used for encryption (saved to key0.key) and the following commands:"
+    - $ sudo apt install cryptsetup
     - $ wget -O key0.key https://gitlab.apertis.org/infrastructure/apertis-image-recipes/-/raw/apertis/v2021dev3/overlays/apertis-update-manager/usr/share/apertis-update-manager
     - $ echo -n "wrong key" > tmp.key
     - $ BUNDLE=<encrypted-static-update-filename>.delta.enc
@@ -29,8 +33,7 @@ metadata:
     - $ sudo cryptsetup luksChangeKey --key-file=key0.key --key-slot=0 /dev/loop0 tmp.key
     - $ for i in {1..7} ; do sudo cryptsetup luksKillSlot --key-file=tmp.key /dev/loop0 $i ; done
     - $ sudo udisksctl loop-delete -b /dev/loop0
-    - "The static encrypted update file with unknown key ($BUNDLE.badkey) should be copied to the third flash drive using the name 'static-update.bundle.enc'."
-    - "A PC must be connected to DUT serial port"
+    - "The static encrypted update file with unknown key ($BUNDLE.badkey) should be copied at the root of the third flash drive using the name 'static-update.bundle.enc'."
 
   expected:
     - "The update was properly applied"