⚡ Cache udid

lib/services/udid.native.dart

@@ -1,5 +1,11 @@
 import 'package:flutter_udid/flutter_udid.dart';
 
+String? _cachedUdid;
+
 Future<String> getUdid() async {
-  return await FlutterUdid.consistentUdid;
+  if (_cachedUdid != null) {
+    return _cachedUdid!;
+  }
+  _cachedUdid = await FlutterUdid.consistentUdid;
+  return _cachedUdid!;
 }