fix: use medkit-gateway for logs check in sensor demo

anomaly-detector and lidar-sim don't emit /rosout logs in CI,
so use medkit-gateway which always has log entries from startup.

Author: bburda

tests/smoke_test.sh

@@ -51,7 +51,7 @@ fi
 
 section "Logs"
 
-assert_non_empty_items "/apps/anomaly-detector/logs"
+assert_non_empty_items "/apps/medkit-gateway/logs"
 
 section "Fault Injection"