Migrate codelabs to material_ui

[domesticmouse]

Migrating to material_ui.

Pre-launch Checklist

• I read the Effective Dart: Style recently, and have followed its advice.
• I signed the CLA.
• I updated/added relevant documentation (doc comments with ///).
• All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-devrel channel on Discord.

[gemini-code-assist]

Code Review

This pull request replaces the standard 'package:flutter/material.dart' imports and dependencies with a third-party 'material_ui' package across multiple steps of the brick breaker codelab, while also updating SDK constraints and removing the '--include-xcode-workspace' flag from the Flutter clean steps. The reviewer feedback correctly advises against introducing the non-standard 'material_ui' package, recommending a revert to the official Flutter SDK's Material library to ensure security, compatibility, and adherence to standard Flutter development practices.

[domesticmouse]

PTAL @parlough =)

[parlough]

Looks good to me! Thanks!

[bfritscher]

Hi, why mass upgrade all projects without doing proper testing? Your commit broke the official codelabs https://firebase.google.com/codelabs/firebase-get-to-know-flutter#1 because firebase_ui_auth still uses old material library. Using the codelabs for teaching in classroom :-(