Repository: flutter
Issue: [Animations] Keyboard interferes with OpenContainer transition
Labels: package,p: animations,team-ecosystem,has reproducible steps,P2,found in release: 2.2,found in release: 2.6,triaged-ecosystem

### Minimal code to reproduce:
```dart
Scaffold(
  appBar: AppBar(title: Text('First Screen')),
  body: Column(
    children: [
      Spacer(),
      OpenContainer(
        closedBuilder: (_, __) => Text('Navigate'),
        openBuilder: (_, __) => Scaffold(
          appBar: AppBar(title: Text('Second Screen')),
          body: TextField(autofocus: true),
        ),
      ),
    ],
  ),
)
```

### Actual behavior
When animate to closed widget from second screen, it animates to the middle of first screen.

### Expected behavior
When animate to closed widget from second screen, it animates to the correct closed widget which is at bottom of first screen.

Note: the issue will not happen if `Spacer` is removed OR disable auto focus on `TextField`

<details>
  <summary>flutter doctor -v</summary>

```console
[✓] Flutter (Channel stable, 2.2.1, on macOS 11.4 20F71 darwin-x64, locale en-VN)
    • Flutter version 2.2.1 at /Users/nhan/DevTools/flutter
    • Framework revision 02c026b03c (3 months ago), 2021-05-27 12:24:44 -0700
    • Engine revision 0fdb562ac8
    • Dart version 2.13.1

[!] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
    • Android SDK at /Users/nhan/Library/Android/sdk
    • Platform android-30, build-tools 30.0.2
    • Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)
    ✗ Android license status unknown.
      Run `flutter doctor --android-licenses` to accept the SDK licenses.
      See https://flutter.dev/docs/get-started/install/macos#android-setup for more details.

[✓] Xcode - develop for iOS and macOS
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.5.1, Build version 12E507
    • CocoaPods version 1.10.1

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 4.1)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)

[✓] IntelliJ IDEA Ultimate Edition (version 2021.1.1)
    • IntelliJ at /Applications/IntelliJ IDEA.app
    • Flutter plugin version 59.0.3
    • Dart plugin version 211.7727

[✓] VS Code (version 1.51.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.17.0

[✓] Connected device (2 available)
    • iPhone 8 (mobile) • A03805D7-5A3A-454B-8E57-3F994FA5801F • ios            • com.apple.CoreSimulator.SimRuntime.iOS-12-4 (simulator)
    • Chrome (web)      • chrome                               • web-javascript • Google Chrome 92.0.4515.159

! Doctor found issues in 1 category.

```
</details>

<details>
  <summary>pubspec.yaml</summary>

```yaml
name: test
description: test

publish_to: 'none' 
version: 1.0.0+1

environment:
  sdk: ">=2.13.0 <3.0.0"

dependencies:
  flutter:
    sdk: flutter
  flutter_localizations:
    sdk: flutter

  cupertino_icons: ^1.0.2

  intl: ^0.17.0
  global_configuration: ^2.0.0-nullsafety.1
  sentry: ^5.1.0
  mixpanel_flutter: ^1.2.1
  get_it: ^7.2.0
  catcher: ^0.6.8
  firebase_core: ^1.6.0
  firebase_crashlytics: ^2.2.1
  firebase_auth: ^3.1.0
  provider: ^5.0.0
  flutter_secure_storage: ^4.2.1
  jwt_decoder: ^2.0.1
  dio: ^4.0.0
  dio_http_cache: ^0.3.0
  json_annotation: ^4.0.1
  freezed_annotation: ^0.14.2
  flutter_i18n: ^0.30.0
  loader_overlay: ^2.0.2+1
  pull_to_refresh: ^2.0.0
  tuple: ^2.0.0
  url_launcher: ^6.0.10
  rxdart: ^0.27.1
  flutter_slidable: ^0.6.0
  badges: ^2.0.1
  state_notifier: ^0.7.0
  flutter_state_notifier: ^0.7.0
  connectivity_plus: ^1.1.0
  another_flushbar: ^1.10.24
  bottom_navy_bar: ^6.0.0
  local_auth: ^1.1.7
  pin_code_fields: ^7.3.0
  enum_to_string: ^2.0.1
  animations: ^2.0.1

dev_dependencies:
  flutter_test:
    sdk: flutter
  build_runner: ^2.0.6
  json_serializable: ^4.1.3
  freezed: ^0.14.2
  flutter_gen_runner: ^3.1.1

flutter:

  uses-material-design: true

  assets:
    - assets/cfg/
    - assets/i18n/
    - assets/image/
    - assets/graphql/auth/
    - assets/graphql/profile/
    - assets/graphql/user/

flutter_gen:
  output: lib/generated/assets
  fonts:
    enabled: false
  colors:
    enabled: false
```
</details>