Add benchmark module with baseline profile generator to improve performance

[adi23arora]

Changes in this PR:

• Replace FocusGroup with focus-restorer APIs from core compose.
• Add handling to gain focus on first item on CategoryMovieListScreen.
• Add benchmarks module with sample StartupBenchmark test and BaselineProfileGenerator test.
• Upgrade AGP(Android Gradle Plugin) to the latest version 8.0.2 to resolve some known issues with baseline profiles.
• Add the baseline profile baseline-prof.txt to the Jetstream app.
• Update README.md to add details about benchmarks module and baseline profiles.
• Add baseline-profiles.md to add details about generating and applying the baseline profiles.