test: set the isPreinstalled flag (#1887)

Author: j-zimnowoda

.github/workflows/integration.yml

@@ -75,7 +75,7 @@ on:
         options:
           - 'true'
           - 'false'
-        default: 'false'
+        default: 'true'
 
 env:
   CACHE_REGISTRY: ghcr.io