fix: fix disconnect when selecting firmware for dfu

lib/main.dart

@@ -57,6 +57,9 @@ class _AbawoBtAppState extends ConsumerState<AbawoBtApp>
   void didChangeAppLifecycleState(AppLifecycleState state) {
     if (state == AppLifecycleState.hidden ||
         state == AppLifecycleState.paused) {
+      if (ref.read(backgroundBluetoothDisconnectSuppressedProvider)) {
+        return;
+      }
       unawaited(_disconnectBluetoothForBackground());
     }
   }