fix(core, web): fix wrong toString js interop in TrustedTypes (#10476)

Author: Lyokone

packages/firebase_core/firebase_core_web/lib/firebase_core_web.dart

@@ -8,6 +8,7 @@ library firebase_core_web;
 import 'dart:async';
 import 'dart:html';
 import 'dart:js';
+import 'dart:js_util';
 
 import 'package:firebase_core_platform_interface/firebase_core_platform_interface.dart';
 import 'package:firebase_core_web/src/interop/js.dart';

packages/firebase_core/firebase_core_web/lib/src/firebase_core_web.dart

@@ -128,7 +128,8 @@ class FirebaseCoreWeb extends FirebasePlatform {
     script.crossOrigin = 'anonymous';
     script.text = '''
       window.ff_trigger_$windowVar = async (callback) => {
-        callback(await import("${trustedUrl?.toString() ?? src}"));
+        console.debug("Initializing Firebase $windowVar");
+        callback(await import("${trustedUrl != null ? callMethod(trustedUrl, 'toString', []) : src}"));
       };
     ''';