Migrate sample to compose

[cy245]

No description provided.

[cy245]

/gemini review

[gemini-code-assist]

Code Review

This pull request successfully migrates the CredentialManager sample app from the traditional View system (Fragments and XML) to Jetpack Compose. The migration is comprehensive, replacing all UI components, navigation, and adapting the logic to a ViewModel-based architecture. The code is now more modern and follows many Compose best practices.

However, there are a few significant areas for improvement. The most critical is the downgrading of several key AndroidX and Kotlin libraries in build.gradle, which is a regression and should be reverted. Additionally, there are architectural concerns, primarily passing Activity and Context instances into ViewModels, which violates MVVM principles and can lead to memory leaks. I've also left comments on improving navigation logic, state handling, and making Compose Previews more robust.

Overall, this is a great step forward for the sample app. Addressing the feedback will make it an even better example of a modern Android application.

[niharika2810]

Hi Chiping, Kindly run Spotless to have copyright, formating and javadocs consitent. WIll review once you are done to focus on other stuff :)