Fix: Remove unused imports in app_test.dart

Author: oriohac

test/widgets/app_test.dart

@@ -1,25 +1,17 @@
 import 'package:checks/checks.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';
-import 'package:path/path.dart';
-import 'package:zulip/api/model/model.dart';
 import 'package:zulip/log.dart';
 import 'package:zulip/model/database.dart';
 import 'package:zulip/model/localizations.dart';
-import 'package:zulip/model/narrow.dart';
 import 'package:zulip/widgets/app.dart';
 import 'package:zulip/widgets/inbox.dart';
-import 'package:zulip/widgets/message_list.dart';
 import 'package:zulip/widgets/page.dart';
-import 'package:zulip/widgets/recent_dm_conversations.dart';
-import 'package:zulip/widgets/subscription_list.dart';
 
-import '../api/fake_api.dart';
 import '../example_data.dart' as eg;
 import '../flutter_checks.dart';
 import '../model/binding.dart';
 import '../test_navigation.dart';
-import 'action_sheet_test.dart';
 import 'dialog_checks.dart';
 import 'page_checks.dart';
 import 'test_app.dart';