waydroid: small simplification

roles/waydroid/tasks/main.yml

@@ -5,14 +5,10 @@
     name: waydroid
     state: present
 
-- name: waydroid | Check whether base image is downloaded
-  stat:
-    path: /var/lib/waydroid/image/system.img
-  register: waydroid_image_check
-
 - name: waydroid | Download base image and initialize
-  command: 'waydroid init -s {{ waydroid.system_type }} -r {{ waydroid.rom_type }}'
-  when: not waydroid_image_check.exists
+  command:
+    cmd: 'waydroid init -s {{ waydroid.system_type }} -r {{ waydroid.rom_type }}'
+    creates: /var/lib/waydroid/image/system.img
 
 - name: waydroid | Add apparmor rules
   blockinfile: