Fix: Corrected getAudioRoutes Typing and Code Cleanup

[palmtown]

This pull request addresses the following improvements:

1. Corrected Typing for getAudioRoutes Method:

• Updated the return type of getAudioRoutes from Promise<void> to Promise<AudioRoute[]> in the TypeScript definitions. This change aligns with the method's actual behavior, enhancing type safety and developer experience.

2. Code Syntax Improvements and Cleanup:

• Resolved various syntax issues and performed general code cleanup to improve readability and maintainability.

These changes aim to enhance the reliability and clarity of the react-native-callkeep library, ensuring accurate typings and cleaner code.