Fix flutter installation on Mac

Need to fix some issues and get clean environment:

flutter doctor
Doctor summary (to see all details, run flutter doctor -v):
[✓] Flutter (Channel stable, 2.8.1, on Mac OS X 10.13.6 17G14042 darwin-x64, locale ar-SA)
[!] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
✗ Flutter requires Android SDK 29 and the Android BuildTools 28.0.3
To update the Android SDK visit https://flutter.dev/docs/get-started/install/macos#android-setup for detailed
instructions.
[!] Xcode - develop for iOS and macOS
✗ Xcode installation is incomplete; a full installation is necessary for iOS development.
Download at: https://developer.apple.com/xcode/download/
Or install Xcode via the App Store.
Once installed, run:
sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer
sudo xcodebuild -runFirstLaunch
! CocoaPods 1.5.3 out of date (1.10.0 is recommended).
CocoaPods is used to retrieve the iOS and macOS platform side's plugin code that responds to your plugin usage on
the Dart side.
Without CocoaPods, plugins will not work on iOS or macOS.
For more info, see https://flutter.dev/platform-plugins
To upgrade see https://guides.cocoapods.org/using/getting-started.html#installation for instructions.
[✓] Chrome - develop for the web
[✓] Android Studio (version 2021.1)
[✓] VS Code (version 1.40.0)
[✓] VS Code (version 1.52.1)
[✓] Connected device (2 available)