Repository: flutter
Issue: [android] `local.properties` is not escaping `:` on Windows
Labels: platform-android,tool,has reproducible steps,P2,found in release: 2.10,found in release: 2.13,team-android,triaged-android

## Steps to Reproduce

1. Create a new project
2. Open `android\local.properties`

**Expected results:**
The colon `:` in values should be preceded by `\`

**Actual results:** <!-- what did you see? -->
```
sdk.dir=C:\\Users\\some_user\\AppData\\Local\\Android\\Sdk
flutter.sdk=c:\\some\\flutter
```
<details>
  <summary>flutter doctor -v</summary>

```
[√] Flutter (Channel master, 2.11.0-0.0.pre.886, on Microsoft Windows [Version 10.0.19042.1466], locale en-US)
    • Flutter version 2.11.0-0.0.pre.886 at c:\use\flutter
    • Upstream repository https://github.com/asashour/flutter.git
    • Framework revision 2bd3e0d914 (7 hours ago), 2022-03-15 04:20:15 -0400
    • Engine revision 6c02eaea3a
    • Dart version 2.17.0 (build 2.17.0-202.0.dev)
    • DevTools version 2.11.4

[!] Android toolchain - develop for Android devices (Android SDK version 32.0.0)
    • Android SDK at C:\Users\ahmed_ashour\AppData\Local\Android\Sdk
    X cmdline-tools component is missing
      Run `path/to/sdkmanager --install "cmdline-tools;latest"`
      See https://developer.android.com/studio/command-line for more details.
    X Android license status unknown.
      Run `flutter doctor --android-licenses` to accept the SDK licenses.
      See https://flutter.dev/docs/get-started/install/windows#android-setup for more details.

[√] Chrome - develop for the web
    • Chrome at C:\Program Files\Google\Chrome\Application\chrome.exe

[√] Visual Studio - develop for Windows (Visual Studio Community 2019 16.11.2)
    • Visual Studio at C:\Program Files (x86)\Microsoft Visual Studio\2019\Community
    • Visual Studio Community 2019 version 16.11.31624.102
    • Windows 10 SDK version 10.0.19041.0

[√] Android Studio (version 2021.1)
    • 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 11.0.11+9-b60-7590822)

[√] IntelliJ IDEA Community Edition (version 2021.3)
    • IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA Community Edition 2021.2.1
    • Flutter plugin version 65.2.4
    • Dart plugin version 213.7227

[√] IntelliJ IDEA Ultimate Edition (version 2022.1)
    • IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA 221.3427.89
    • Flutter plugin can be installed from:
       https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin version 221.3427.93

[√] VS Code (version 1.64.2)
    • VS Code at C:\Users\ahmed_ashour\AppData\Local\Programs\Microsoft VS Code
    • Flutter extension version 3.34.0

[√] Connected device (4 available)
    • SM A505FN (mobile) • R58MA65MFJF • android-arm64  • Android 11 (API 30)
    • Windows (desktop)  • windows     • windows-x64    • Microsoft Windows [Version 10.0.19042.1466]
    • Chrome (web)       • chrome      • web-javascript • Google Chrome 99.0.4844.51
    • Edge (web)         • edge        • web-javascript • Microsoft Edge 99.0.1150.39

[√] HTTP Host Availability
    • All required HTTP hosts are available

! Doctor found issues in 1 category.
```

</details>

The documentation of Java [Properties](https://docs.oracle.com/javase/8/docs/api/java/util/Properties.html#store-java.io.Writer-java.lang.String-) mentions:

> The key and element characters #, !, =, and : are written with a preceding backslash to ensure that they are properly loaded.

![image](https://user-images.githubusercontent.com/2410127/158406085-73194844-5646-4cdd-94b2-dc3f7c822ea4.png)

Should we also escape the other characters (`#`, `!` and `=`)?