Repository: flutter
Issue: [google_maps_flutter_web] Missing longPress support on Mobile Web
Labels: p: maps,platform-web,package,has reproducible steps,P2,found in release: 2.8,found in release: 2.9,team-web,triaged-web

We trying to use the `longPress` event provided by the google maps flutter plugin.
The maps the setup roughly looks like this:

```
@override
  Widget build(BuildContext context) {
    return Scaffold(
      body:GoogleMap(
          mapType: MapType.hybrid,
          onLongPress: (latLn) {
                  widget.onPinDropped(latLng);
          }
          onMapCreated: (GoogleMapController controller) {
            _controller.complete(controller);
          },
        ),
      floatingActionButton: FloatingActionButton.extended(
        onPressed: _goToTheLake,
        label: const Text('To the lake!'),
        icon: const Icon(Icons.directions_boat),
      ),
    );
  }
```

While the `longPress` works fine on Mobile app, with the standard long press, the same event on Desktop Web fires with a `mouse right click` as well.
But on Mobile Web, we dont get any events fired on for this.
Is there a way we get this event working on Mobile web.


<details>
  <summary>flutter doctor -v</summary>

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```
[✓] Flutter (Channel stable, 2.5.3, on macOS 11.6 20G165 darwin-x64, locale en-US)
    • Flutter version 2.5.3 at /Users/ahetawal/sdk/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 18116933e7 (9 weeks ago), 2021-10-15 10:46:35 -0700
    • Engine revision d3ea636dc5
    • Dart version 2.14.4

[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
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    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7281165)
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    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7281165)

[✓] IntelliJ IDEA Ultimate Edition (version 2021.2.1)
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[✓] IntelliJ IDEA Ultimate Edition (version 2021.2.1)
    • IntelliJ at /Users/ahetawal/Library/Application Support/JetBrains/Toolbox/apps/IDEA-U/ch-0/212.5080.55/IntelliJ IDEA.app
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[✓] VS Code (version 1.59.0)
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[✓] Connected device (2 available)
    • iPhone 11 (mobile) • 15249398-F752-49BD-9F8C-E7DD89D48344 • ios            • com.apple.CoreSimulator.SimRuntime.iOS-14-5 (simulator)
    • Chrome (web)       • chrome                               • web-javascript • Google Chrome 96.0.4664.93
```