Repository: flutter
Issue: TextFormField does not support obscureText and textCapitalisation
Labels: a: text input,framework,f: material design,has reproducible steps,P3,found in release: 3.10,team-design,triaged-design,found in release: 3.13

### Is there an existing issue for this?

- [X] I have searched the [existing issues](https://github.com/flutter/flutter/issues)
- [X] I have read the [guide to filing a bug](https://flutter.dev/docs/resources/bug-reports)

### Steps to reproduce

1. In TextFormField, add obscureText to true and assign textCapitalization to TextCapitalization.characters

### Expected results

The keyboard should be capitalized in both show and hide character in TextFormField with obscureText

### Actual results

1. In TextFormField, add obscureText to true and assign textCapitalization to TextCapitalization.characters
2. The device keyboard is capitalised when the show text is clicked but when the hide text is clicked, the keyboard defaults to lowercase characters.

### Code sample

<details><summary>Code sample</summary>

```dart
TextFormField(
  textCapitalization: TextCapitalization.characters,
  obscureText: true,
);
```

</details>


### Screenshots or Video

<details>
<summary>Screenshots / Video demonstration</summary>

[Upload media here]

</details>


### Logs

<details><summary>Logs</summary>

```console
Reloaded 1 of 1588 libraries in 334ms (compile: 79 ms, reload: 83 ms, reassemble: 155 ms).
Reloaded 1 of 1588 libraries in 318ms (compile: 63 ms, reload: 133 ms, reassemble: 108 ms).
Reloaded 1 of 1588 libraries in 201ms (compile: 20 ms, reload: 62 ms, reassemble: 110 ms).
Reloaded 58 of 1588 libraries in 408ms (compile: 187 ms, reload: 104 ms, reassemble: 101 ms).
```

</details>


### Flutter Doctor output

<details><summary>Doctor output</summary>

```console
[✓] Flutter (Channel stable, 3.3.8, on macOS 13.0.1 22A400 darwin-arm, locale en-IN)
    • Flutter version 3.3.8 on channel stable at /Users/admin/Workspace/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 52b3dc25f6 (9 months ago), 2022-11-09 12:09:26 +0800
    • Engine revision 857bd6b74c
    • Dart version 2.18.4
    • DevTools version 2.15.0

[✓] Android toolchain - develop for Android devices (Android SDK version 33.0.0)
    • Android SDK at /Users/admin/Library/Android/sdk
    • Platform android-33, build-tools 33.0.0
    • ANDROID_HOME = /Users/admin/Library/Android/sdk
    • ANDROID_SDK_ROOT = /Users/admin/Library/Android/sdk
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.12+0-b1504.28-7817840)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 14.0)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Build 14A309
    • CocoaPods version 1.11.3

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2021.2)
    • 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 11.0.12+0-b1504.28-7817840)

[✓] VS Code (version 1.80.1)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension version 3.68.0

[✓] Connected device (3 available)
    • Client iPhone 14 (mobile) • A77B6DEE-BB30-4428-B1B3-5E1018973062 • ios            •
      com.apple.CoreSimulator.SimRuntime.iOS-16-0 (simulator)
    • macOS (desktop)           • macos                                • darwin-arm64   • macOS 13.0.1 22A400 darwin-arm
    • Chrome (web)              • chrome                               • web-javascript • Google Chrome 114.0.5735.248

[✓] HTTP Host Availability
    • All required HTTP hosts are available

• No issues found!
```

</details>