title: How to fix AutoValidateMode issue on Flutter?
body: <p>I am making an app for Phone Authentication with Firebase and Flutter. I am not using any form field but I am getting error of <code>AutoValidateMode</code> Not Found. I have been looking for solution on net since 2 days but couldn't able to find one. The code is as follow.</p>
  <pre><code>import 'dart:async';
  
  import 'package:firebase_auth/firebase_auth.dart';
  import 'package:firebase_core/firebase_core.dart';
  import 'package:flutter/material.dart';
  import 'package:sms_autofill/sms_autofill.dart';
  
  Future&lt;void&gt; main() async {
    WidgetsFlutterBinding.ensureInitialized();
    await Firebase.initializeApp();
    runApp(MyApp());
  }
  
  class MyApp extends StatelessWidget {
    @override
    Widget build(BuildContext context) {
      return MaterialApp(
        theme: ThemeData(
          primarySwatch: Colors.green,
        ),
        home: MyHomePage(title: 'Phone Auth'),
      );
    }
  }
  
  class MyHomePage extends StatefulWidget {
    MyHomePage({Key key, this.title}) : super(key: key);
  
    final String title;
  
    @override
    _MyHomePageState createState() =&gt; _MyHomePageState();
  }
  
  class _MyHomePageState extends State&lt;MyHomePage&gt; {
    final FirebaseAuth _auth = FirebaseAuth.instance;
  
    final _scaffoldKey = GlobalKey&lt;ScaffoldState&gt;();
  
    final TextEditingController _phoneNumberController = TextEditingController();
    final TextEditingController _smsController = TextEditingController();
    String _verificationId;
    final SmsAutoFill _autoFill = SmsAutoFill();
  
    @override
    Widget build(BuildContext context) {
      return Scaffold(
          appBar: AppBar(
            title: Text(widget.title),
          ),
          key: _scaffoldKey,
          resizeToAvoidBottomInset: false,
          body: Padding(
            padding: const EdgeInsets.all(8),
            child: Padding(
                padding: EdgeInsets.all(16),
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: &lt;Widget&gt;[
                      TextFormField(
                      controller: _phoneNumberController,
                      decoration: const InputDecoration(
                          labelText: 'Phone number (+xx xxx-xxx-xxxx)'),
                    ),],
                )),
          ));
    }
  }
  
  </code></pre>
  <p>For this code, I am getting error as follow.</p>
  <pre><code>../../../../.pub-cache/hosted/pub.dartlang.org/pin_input_text_field-3.3.0/lib/src/widget/pin_widget.dart:402:5: Error: Type 'AutovalidateMode' not found.
      AutovalidateMode autovalidateMode = AutovalidateMode.disabled,
      ^^^^^^^^^^^^^^^^
  ../../../../.pub-cache/hosted/pub.dartlang.org/pin_input_text_field-3.3.0/lib/src/widget/pin_widget.dart:402:5: Error: 'AutovalidateMode' isn't a type.
      AutovalidateMode autovalidateMode = AutovalidateMode.disabled,
      ^^^^^^^^^^^^^^^^
  ../../../../.pub-cache/hosted/pub.dartlang.org/pin_input_text_field-3.3.0/lib/src/widget/pin_widget.dart:402:41: Error: Getter not found: 'AutovalidateMode'.
      AutovalidateMode autovalidateMode = AutovalidateMode.disabled,
                                          ^^^^^^^^^^^^^^^^
  ../../../../.pub-cache/hosted/pub.dartlang.org/pin_input_text_field-3.3.0/lib/src/widget/pin_widget.dart:436:13: Error: No named parameter with the name 'autovalidateMode'.
              autovalidateMode: autovalidateMode,
              ^^^^^^^^^^^^^^^^
  
  </code></pre>
  <p>How to fix this issue? Where to edit <code>AutoValidateMode</code> to always?
  Your help is very grateful.</p>