Repository: flutter
Issue: [TextField] alignLabelWithHint does not have any effect when used with UnderlineInputBorder
Labels: a: text input,f: material design,has reproducible steps,P2,found in release: 3.16,found in release: 3.19,team-text-input,triaged-text-input

### Steps to reproduce

 - Run the code sample below
 - check the difference of behavior between UnderlineInputBorder and OutlineInputBorder

### Expected results

When `alignLabelWithHint` is set to false with `UnderlineInputBorder`, the label should align the same way `OutlineInputBorder` does

### Actual results

When `alignLabelWithHint` is set to false it still aligns with the hint

### Use case

For real world scenario, I'd like to have the label placed at the start here:

![image](https://github.com/flutter/flutter/assets/22280985/5f6c18d6-550c-426e-a3b5-422e5e168c8e)


### Code sample

<details open><summary>Code sample</summary>

```dart

import 'package:flutter/material.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: Scaffold(
        body: Center(
          child: TextField(
            decoration: InputDecoration(
              // border: const UnderlineInputBorder(),
              border: const OutlineInputBorder(),
              prefixIcon: Container(
                color: Colors.amber,
                width: 100,
                height: 48,
              ),
              labelText: 'My label',
              alignLabelWithHint: false,
            ),
          ),
        ),
      ),
    );
  }
}

```

</details>


### Screenshots or Video

### Underline

![image](https://github.com/flutter/flutter/assets/22280985/fd708b2e-44d8-4df9-8435-5a1069f1989c)

^ I can already achieve that behavior with `alignLabelWithHint: true`, for my personal use case I need to align it like the outline does below

### Outline

![image](https://github.com/flutter/flutter/assets/22280985/d036b680-b955-4525-82d7-cc1a064a2af2)


### Logs

_No response_

### Flutter Doctor output

<details open><summary>Doctor output</summary>

```console
[√] Flutter (Channel stable, 3.16.9, on Microsoft Windows [Version 10.0.22631.3007], locale en-BE)
    • Flutter version 3.16.9 on channel stable at C:\dev\flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 41456452f2 (10 days ago), 2024-01-25 10:06:23 -0800
    • Engine revision f40e976bed
    • Dart version 3.2.6
    • DevTools version 2.28.5

[√] Windows Version (Installed version of Windows is version 10 or higher)

[√] Android toolchain - develop for Android devices (Android SDK version 34.0.0)
    • Android SDK at C:\Users\cedva\AppData\Local\Android\sdk
    • Platform android-34, build-tools 34.0.0
    • Java binary at: C:\Program Files\Android\Android Studio\jbr\bin\java
    • Java version OpenJDK Runtime Environment (build 17.0.7+0-b2043.56-10550314)
    • All Android licenses accepted.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Visual Studio - develop Windows apps (Visual Studio Build Tools 2019 16.11.32)
    • Visual Studio at C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools
    • Visual Studio Build Tools 2019 version 16.11.34301.259
    • Windows 10 SDK version 10.0.19041.0

[√] Android Studio (version 2023.1)
    • Android Studio at C:\Program Files\Android\Android Studio
    • 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 17.0.7+0-b2043.56-10550314)

[√] VS Code (version 1.86.0)
    • VS Code at C:\Users\cedva\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.82.0

[√] Connected device (3 available)
    • Windows (desktop) • windows • windows-x64    • Microsoft Windows [Version 10.0.22631.3007]
    • Chrome (web)      • chrome  • web-javascript • Google Chrome 121.0.6167.140
    • Edge (web)        • edge    • web-javascript • Microsoft Edge 121.0.2277.98

[√] Network resources
    • All expected network resources are available.

• No issues found!
```

</details>