はじめに

$ flutter doctor                                      
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 2.0.3, on macOS 11.1 20C69 darwin-x64, locale ja-JP)
[!] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
    ✗ Android license status unknown.
      Run `flutter doctor --android-licenses` to accept the SDK licenses.
      See https://flutter.dev/docs/get-started/install/macos#android-setup for more details.
[✓] Xcode - develop for iOS and macOS
[✓] Chrome - develop for the web
[✓] Android Studio (version 4.2)
[✓] VS Code (version 1.64.0)
[✓] Connected device (1 available)

! Doctor found issues in 1 category.

flutter doctorが失敗します・・・・

Android Studioを起動

Preferences＞Appearance & Behavior＞System Settings＞Android SDK＞SDK Toolsへ移動
（長い・・）

Android SDK Command-line Toolsにチェックをつけて、Applyを選択

インストール後、再度flutter doctorを実行すると問題がなくなっています！

flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 2.0.3, on macOS 11.1 20C69 darwin-x64, locale ja-JP)
[✓] Android toolchain - develop for Android devices (Android SDK version 30.0.2)
[✓] Xcode - develop for iOS and macOS
[✓] Chrome - develop for the web
[✓] Android Studio (version 4.2)
[✓] VS Code (version 1.64.0)
[✓] Connected device (1 available)

• No issues found!