Fix issues reported by ansible-lint

_ansible/roles/watchtower/tasks/main.yml

@@ -4,10 +4,11 @@
     - watchtower
     - container
   block:
-    - import_tasks: deploy-common-service.yml
-    
+    - name: Import tasks to deploy common service
+      ansible.builtin.import_tasks: tasks/deploy-common-service.yml
+
     - name: Copy the run-once script
       ansible.builtin.copy:
         src: run-once.sh
         dest: "{{ (service_path, 'run-once.sh') | path_join }}"
-        mode: '0755'
+        mode: "0755"

_ansible/roles/watchtower/vars/main.yml

@@ -1,3 +1,4 @@
+---
 svc:
   name: watchtower