Repository: flutter
Issue: DraggableScrollableSheet from showModalBottomSheet does not carry momentum from fling to expand the sheet
Labels: framework,f: material design,f: scrolling,P2,team-design,triaged-design



## Steps to Reproduce

<!-- Please include full steps to reproduce so that we can reproduce the problem. -->

Paste the code from the sample below under MaterialApp's home property
Run the app and press the bugs button
A draggable scrollable sheet will appear.
**Actual results:** <!-- what did you see? -->
If you begin dragging the sheet fast enough and immediately release the finger, it will snap to the top and won't scroll the ListView further (but it definitely should though). However, it works fine if you keep holding the finger. Same thing applies when you scroll in opposite direction.
To reproduce it, all you have to do is to touch the screen and swipe it up and immediately release the finger. The bottomsheet will expand to top, but the inner listview won't scroll no matter how fast you've swiped, unless you keep holding the finger for a little longer.
Here is the video (you can see the semi-transparent circle behind the cursor indicating how much do I hold the LMB):

https://user-images.githubusercontent.com/54116985/207344715-4213c6aa-2710-45e8-afe9-dc0518b093da.mov


**Expected results:** <!-- what did you want to see? -->
The inner list should also start scrolling when the bottomSheet has reached the maximum height, here is an example:

https://user-images.githubusercontent.com/54116985/207346391-a92cb875-6942-4e80-ae72-ff4f9833ad74.mov







<details>
<summary>Code sample</summary>

<!--
      Please create a minimal reproducible sample that shows the problem
      and attach it below between the lines with the backticks.

      To create it you can use `flutter create bug` command and update the `main.dart` file.

      Alternatively, you can use https://dartpad.dev/
      which is capable of creating and running small Flutter apps.

      Without this we will unlikely be able to progress on the issue, and because of that
      we regretfully will have to close it.
-->

```dart
import 'package:flutter/material.dart';

class TestScreen extends StatelessWidget {
  const TestScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: ElevatedButton(
          onPressed: () {
            showModalBottomSheet(
              enableDrag: true,
              useSafeArea: true,
              clipBehavior: Clip.hardEdge,
              shape: const RoundedRectangleBorder(
                borderRadius: BorderRadius.only(
                  topLeft: Radius.circular(20),
                  topRight: Radius.circular(20),
                ),
              ),
              context: context,
              isScrollControlled: true,
              builder: (context) {
                return DraggableScrollableSheet(
                  expand: false,
                  initialChildSize: 0.8,
                  snap: true,
                  snapSizes: const [0.8, 1.0],
                  builder: (context, scrollController) {
                    return CustomScrollView(
                      controller: scrollController,
                      physics: const ClampingScrollPhysics(),
                      slivers: [
                        SliverPersistentHeader(
                          delegate: TestSliverAppBar(),
                          pinned: true,
                        ),
                        SliverList(
                          delegate: SliverChildBuilderDelegate(
                            (_, index) => ListTile(
                              title: Text("Index: $index"),
                            ),
                            childCount: 50,
                          ),
                        )
                      ],
                    );
                  },
                );
              },
            );
          },
          child: const Text(
            'bugs',
          ),
        ),
      ),
    );
  }
}

class TestSliverAppBar extends SliverPersistentHeaderDelegate {
  @override
  Widget build(
      BuildContext context, double shrinkOffset, bool overlapsContent) {
    return Container(
      color: Colors.pink,
    );
  }

  @override
  double get maxExtent => 100;

  @override
  double get minExtent => 50;

  @override
  bool shouldRebuild(covariant SliverPersistentHeaderDelegate oldDelegate) =>
      true;
}

```

</details>

<details>
  <summary>Logs</summary>



<!-- Finally, paste the output of running `flutter doctor -v` here. -->

```
[!] Flutter (Channel master, 3.6.0-14.0.pre.2, on macOS 12.6 21G115 darwin-arm64, locale ru-RU)
    • Flutter version 3.6.0-14.0.pre.2 on channel master at /Users/gidrokolbaska/Developer/flutter
    ! Warning: `dart` on your path resolves to /opt/homebrew/Cellar/dart/2.16.0/libexec/bin/dart, which is not inside your
      current Flutter SDK checkout at /Users/gidrokolbaska/Developer/flutter. Consider adding
      /Users/gidrokolbaska/Developer/flutter/bin to the front of your path.
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 7572ce907f (35 hours ago), 2022-12-01 01:07:29 -0500
    • Engine revision 51356bf895
    • Dart version 2.19.0 (build 2.19.0-444.0.dev)
    • DevTools version 2.20.0
    • If those were intentional, you can disregard the above warnings; however it is recommended to use "git" directly to
      perform update checks and upgrades.

[✓] Android toolchain - develop for Android devices (Android SDK version 32.1.0-rc1)
    • Android SDK at /Users/gidrokolbaska/Library/Android/sdk
    • Platform android-32, build-tools 32.1.0-rc1
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.11+0-b60-7772763)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 14.0.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 14A400
    • CocoaPods version 1.11.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2021.1)
    • 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 11.0.11+0-b60-7772763)

[✓] VS Code (version 1.73.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.34.0

[✓] Connected device (3 available)
    • iPhone 12 (mobile) • 070B14C3-C297-4A54-A136-A502B61105DF • ios            •
      com.apple.CoreSimulator.SimRuntime.iOS-16-0 (simulator)
    • macOS (desktop)    • macos                                • darwin-arm64   • macOS 12.6 21G115 darwin-arm64
    • Chrome (web)       • chrome                               • web-javascript • Google Chrome 108.0.5359.71

[✓] HTTP Host Availability
    • All required HTTP hosts are available

! Doctor found issues in 1 category.
```

</details>