Repository: flutter
Issue: AppBar is not clickable after setting primary to false on iOS
Labels: platform-ios,framework,f: material design,f: gestures,has reproducible steps,P2,found in release: 3.3,found in release: 3.7,team-design,triaged-design

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I would like to add some widgets above AppBar, but after set it's parameter primary to false get locked cliсkable area atop of it. It reproduces on iOS, on Android it works good.
In `scaffold.dart` I found that code:
```
    switch (themeData.platform) {
      case TargetPlatform.iOS:
      case TargetPlatform.macOS:
        _addIfNonNull(
          children,
          GestureDetector(
            behavior: HitTestBehavior.opaque,
            onTap: _handleStatusBarTap,
            // iOS accessibility automatically adds scroll-to-top to the clock in the status bar
            excludeFromSemantics: true,
          ),
          _ScaffoldSlot.statusBar,
          removeLeftPadding: false,
          removeTopPadding: true,
          removeRightPadding: false,
          removeBottomPadding: true,
        );
        break;
      case TargetPlatform.android:
      case TargetPlatform.fuchsia:
      case TargetPlatform.linux:
      case TargetPlatform.windows:
        break;
    }
```
As we can see, GestureDetector handles for tapping statusBar's area for iOS but when we set primary to false this area locks an AppBar's actions.
## Steps to Reproduce

<!-- You must include full steps to reproduce so that we can reproduce the problem. -->

1. Run `flutter create bug`.
2. Update build of _MyHomePageState in the main.dart as follows: <!-- include every file that is different from the template app! -->
```
Widget build(BuildContext context) {
    return Column(
      children: [
        const SizedBox(height: 60, width: 100,),
        Expanded(
          child: Scaffold(
            drawer: Drawer(child: Center(child: Container(color: Colors.blue,))),
            primary: false,
            appBar: AppBar(
              primary: false,
              title: Text(widget.title),
            ),
            body: Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: <Widget>[
                  Text(
                    'You have pushed the button this many times:',
                  ),
                  Text(
                    '$_counter',
                    style: Theme.of(context).textTheme.headline4,
                  ),
                ],
              ),
            ),
            floatingActionButton: FloatingActionButton(
              onPressed: _incrementCounter,
              tooltip: 'Increment',
              child: Icon(Icons.add),
            ),
          ),
        ),
      ],
    );
  }
```
3. ... <!-- describe how to reproduce the problem -->

**Expected results:** <!-- what did you want to see? -->
A tap to home button will open a drawer

**Actual results:** <!-- what did you see? -->
A tap to home button do nothing

<details>
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<!-- Finally, paste the output of running `flutter doctor -v` here. -->

```
[✓] Flutter (Channel unknown, 1.20.2, on Mac OS X 10.15.6 19G2021, locale ru-RU)
    • Flutter version 1.20.2 at /Users/sizyikh/Documents/sdk/flutter
    • Framework revision bbfbf1770c (3 months ago), 2020-08-13 08:33:09 -0700
    • Engine revision 9d5b21729f
    • Dart version 2.9.1

 
[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
    • Android SDK at /Users/sizyikh/Documents/sdk/Android
    • Platform android-30, build-tools 30.0.2
    • ANDROID_HOME = /Users/sizyikh/Documents/sdk/Android
    • 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-b3-6222593)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 12.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 12.1, Build version 12A7403
    • CocoaPods version 1.9.3

[✓] Android Studio (version 4.0)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin version 49.0.2
    • Dart plugin version 193.7547
    • Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)

[✓] VS Code (version 1.50.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.16.0

[✓] Connected device (1 available)
    • iPhone Xs (mobile) • 1538D24C-98F6-43C6-B360-52143C4D8303 • ios • com.apple.CoreSimulator.SimRuntime.iOS-12-0 (simulator)

• No issues found!

```

</details>