Repository: flutter
Issue: `tester.pumpWidget` doesn't show "Tests finished" message when Running test on device
Labels: a: tests,framework,has reproducible steps,P2,found in release: 2.5,found in release: 2.6,team-framework,triaged-framework

## Steps to Reproduce

When running tests on device, it should end with "Tests finished" message, however this never happens

Here's a code in question 

https://github.com/flutter/flutter/blob/9421627324c27c5256e87fe3244a8867de9f338b/packages/flutter_test/lib/src/binding.dart#L811

If we add another `pump` there, it starts working

1. Execute `flutter run` on the code sample

**Expected results:** "Tests finished" message

**Actual results:** Black screen

<details>
<summary>Code sample</summary>

```dart
import 'package:flutter/material.dart';
import 'package:flutter_test/flutter_test.dart';

void main() {
  testWidgets('Counter increments smoke test', (WidgetTester tester) async {
    await tester.pumpWidget(Container());
  });
}
```

</details>

<details>
  <summary>Logs</summary>

```
I/flutter (29033): 00:00 +0: Counter increments smoke test
I/flutter (29033): 00:00 +1: All tests passed!
```

```
[√] Flutter (Channel master, 2.6.0-12.0.pre.345, on Microsoft Windows [Version 10.0.19041.1237], locale ru-RU)
    • Flutter version 2.6.0-12.0.pre.345 at C:\dev\src\flutter
    • Upstream repository git@github.com:nt4f04und/flutter.git
    • FLUTTER_GIT_URL = git@github.com:nt4f04und/flutter.git
    • Framework revision 240d209345 (6 hours ago), 2021-10-14 07:04:26 -0700
    • Engine revision ea7fa6a65f
    • Dart version 2.15.0 (build 2.15.0-211.0.dev)

[!] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
    • Android SDK at C:\Users\danya\AppData\Local\Android\sdk
    X cmdline-tools component is missing
      Run `path/to/sdkmanager --install "cmdline-tools;latest"`
      See https://developer.android.com/studio/command-line for more details.
    X Android license status unknown.
      Run `flutter doctor --android-licenses` to accept the SDK licenses.
      See https://flutter.dev/docs/get-started/install/windows#android-setup for more details.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Visual Studio - develop for Windows (Visual Studio Community 2019 16.7.7)
    • Visual Studio at C:\Program Files (x86)\Microsoft Visual Studio\2019\Community
    • Visual Studio Community 2019 version 16.7.30621.155
    • Windows 10 SDK version 10.0.19041.0

[√] Android Studio (version 4.1)
    • Android Studio at C:\Program Files\Android\Android Studio
    • 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-b01)

[√] IntelliJ IDEA Community Edition (version 2020.3)
    • IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2020.3.3
    • 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

[√] VS Code (version 1.61.0)
    • VS Code at C:\Users\danya\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.27.0

[√] Connected device (4 available)
    • sdk gphone x86 (mobile) • emulator-5554 • android-x86    • Android 11 (API 30) (emulator)
    • Windows (desktop)       • windows       • windows-x64    • Microsoft Windows [Version 10.0.19041.1237]
    • Chrome (web)            • chrome        • web-javascript • Google Chrome 94.0.4606.81
    • Edge (web)              • edge          • web-javascript • Microsoft Edge 94.0.992.38

! Doctor found issues in 1 category.
```
</details>