VPN 3436 notification refactor (#5384) * Cleanup the Notification Code * Notification code cleanup * Fix serialisation * Cleanups * revert unrelated changes * cleanups * Formatting * Update android/daemon/src/main/java/org/mozilla/firefox/vpn/daemon/NotificationUtil.kt Co-authored-by: Beatriz Rizental <[email protected]> * fixes c: Co-authored-by: Beatriz Rizental <[email protected]>