Adds Firefox-specific detection and logic to the AutoplayHandler to better handle autoplay restrictions in Firefox. This includes user gesture detection, delayed playback attempts, custom error handling, and user notifications to prompt interaction for enabling playback and sound. The changes ensure a more reliable autoplay experience across browsers, especially addressing Firefox's stricter autoplay policies.
Eliminated inline background color styles for the progressControl and its holder in EndScreenHandler. This change relies on default or external styles for a cleaner implementation.
