Swiping back while flushbar is dismissing freezes swiping animation

[tomk9]

Video:

LDQK8580.MP4

Steps to Reproduce:

iPhone only

1. Go to next page.
2. Show flushbar.
3. Start swiping back and release while flushbar is dismissing.
4. Swiping animation freezes.

Code:

import 'package:flushbar/flushbar.dart';
import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flushbar Error',
      theme: ThemeData(
        primarySwatch: Colors.blue,
        visualDensity: VisualDensity.adaptivePlatformDensity,
      ),
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('First Page'),
      ),
      body: Center(
        child: RaisedButton(
          onPressed: () {
            Navigator.push(
              context,
              MaterialPageRoute(
                builder: (context) => SecondPage(),
              ),
            );
          },
          child: Text(
            'Go to second page',
          ),
        ),
      ),
    );
  }
}

class SecondPage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Second Page'),
      ),
      body: Center(
        child: RaisedButton(
          onPressed: () {
            Flushbar(
              title: "Hey Ninja",
              message:
                  "Lorem Ipsum is simply dummy text of the printing and typesetting industry",
              duration: Duration(seconds: 3),
            )..show(context);
          },
          child: Text(
            'Show flushbar',
          ),
        ),
      ),
    );
  }
}

The same issue as cmdrootaccess/another-flushbar#7