This commit significantly refactors the `PolylineProgressDemoActivity` to align with modern Android development practices and better showcase the library's features.

Key changes include:
- **View Binding**: Replaced `findViewById` with View Binding for type-safe and more concise access to UI components. This required enabling `viewBinding` in the demo's `build.gradle.kts`.
- **Lifecycle-Aware Coroutines**: The animation now uses `lifecycleScope`, ensuring the coroutine is automatically canceled when the Activity is destroyed, preventing memory leaks.
- **State Management**: Replaced multiple `MutableLiveData` instances with a single `LiveData<AnimationState>` data class. This creates a single source of truth for the animation's state, leading to more predictable and maintainable UI updates.
- **Code Structure and Documentation**: The code has been reorganized into smaller, more focused functions. Extensive KDoc comments have been added to explain the implementation, highlight the use of `SphericalUtil`, and document the modern Android patterns being used.