Migrate JankStatsSample from Fragments to Jetpack Compose and Navigation3

* Replace Fragment-based UI and Navigation Component with Jetpack Compose and Jetpack Navigation3.
* Remove `MessageListFragment`, `MessageContentFragment`, `ComposeListFragment`, `MessageListAdapter`, and associated XML layout files and navigation graphs.
* Add Jetpack Compose UI components (`MessageList`, `MessageContentScreen`, `JankStatsScaffold`) and Navigation3 components (`NavKeys`, `NavigationState`, `Navigator`).
* Refactor `JankLoggingActivity` and `JankAggregatorActivity` to `ComponentActivity` using `setContent` with Compose UI and Lifecycle effects.
* Bump `compileSdk` and `targetSdk` to 36, and `minSdk` to 23.
* Add `navigation3` and `kotlinx-serialization` dependencies to Gradle configuration.