Update matching prompt in common boot template

Earlier, we were using an old kernel and rootfs from 18.09.xx.

We've now switched to using a much newer one from v2020, which is where
it requires an update of our assumpt login prompts

This fix is a cherry-pick of commit id: 7a5c59f4292dccc5e02416f792fd3d96bc3c1488
which has already been applied in apertis-test-cases repository against
v2021dev3

Signed-off-by: Ritesh Raj Sarraf <ritesh.sarraf@collabora.com>

templates/common-boot-tpl.yaml

@@ -70,7 +70,7 @@ actions:
       prompts:
         - 'nfsuser@apertis:'
         - '\$ '
-        - '\# '
+        - '/home/user # '
       auto_login:
         login_prompt: 'apertis-nfs login:'
         username: nfsuser