Revert "Add API to services package that overrides HTTP ban (#54243)" (#54519)

This reverts commit 9eb2a2ad.

packages/flutter/lib/services.dart

@@ -22,7 +22,6 @@ export 'src/services/message_codec.dart';
 export 'src/services/message_codecs.dart';
 export 'src/services/platform_channel.dart';
 export 'src/services/platform_messages.dart';
-export 'src/services/platform_network.dart';
 export 'src/services/platform_views.dart';
 export 'src/services/raw_keyboard.dart';
 export 'src/services/raw_keyboard_android.dart';

packages/flutter/lib/src/services/platform_network.dart

-// Copyright 2014 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-import 'dart:async';
-
-/// Allows an operation executed via [action] to access insecure HTTP URLs.
-///
-/// On some platforms (notably iOS and Android), HTTP is disallowed by default.
-/// You should strive to access secure URLs from your app, but we recognize that
-/// sometimes that is not possible. In such cases, use the function below to
-/// allow access to HTTP URLs.
-///
-/// Sample usage:
-///
-/// ```dart
-/// import 'package:flutter/services.dart' as services;
-///
-/// final Image image = services.allowHttp(() => Image.network('http://some_insecure_url');
-/// ```
-///
-/// Best Practices:
-/// - Do not wrap your entire app with [allowHttp]. Wrap *exactly* what you need and nothing more.
-/// - Avoid libraries that require accessing HTTP URLs.
-T allowHttp<T>(T action()) {
-  return runZoned<T>(action, zoneValues: <Symbol, bool>{#dart.library.io.allow_http: true});
-}

packages/flutter/test/services/platform_network_test.dart

-// Copyright 2014 The Flutter Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-import 'dart:async';
-import 'dart:io';
-
-import 'package:flutter/services.dart';
-
-import 'package:flutter_test/flutter_test.dart';
-
-void main() {
-  const Symbol _symbol = #dart.library.io.allow_http;
-
-  test('AllowHTTP sets the correct zone variable', () async {
-    expect(Zone.current[_symbol], isNull);
-    allowHttp(() {
-      expect(Zone.current[_symbol], isTrue);
-    });
-  });
-
-  // This test ensures the zone variable used in Dart SDK does not change.
-  //
-  // If this symbol changes, then update [allowHttp] function as well.
-  test('Zone variable can override HTTP behavior', () async {
-    final HttpClient httpClient = HttpClient();
-    try {
-      await runZoned(
-        () async => await httpClient.getUrl(Uri.parse('http://${Platform.localHostname}')),
-        zoneValues: <Symbol, bool>{_symbol: false},
-      );
-      fail('This should have thrown a StateError. '
-           'Check if the symbol for setting allow_http behavior has changed');
-    } on StateError catch(e) {
-      expect(e.message, contains('Insecure HTTP is not allowed by the current platform'));
-    }
-  });
-}