[Audiobookshelf] Add persistent lock screen and notification center media controls for Android (stre

### Type of Enhancement None ### Describe the Feature/Enhancement Add lock screen and notification center media playback controls for the Android app when streaming audiobooks. Currently, when playing an audiobook via streaming, no media controls appear in the notification center or on the lock screen. This forces users to unlock their phone and open the app every time they want to control playback. ### Why would this be helpful? Other audio apps like Spotify and Audible correctly display their media controls in the notification center and on the lock screen, allowing quick playback control (play/pause, skip forward/backward, progress bar) without unlocking the phone. Audiobookshelf should provide the same convenient experience. This is especially important for audiobooks since listening sessions are typically longer and users frequently need to pause or adjust playback while doing other things. ### Future Implementation (Screenshot) Expected behavior: Similar to Spotify/Audi