Autoplay the next voice message if it is the next timeline item. (#6089)

ElementX/Sources/Services/MediaPlayer/MediaPlayerProvider.swift

@@ -6,11 +6,14 @@
 // Please see LICENSE files in the repository root for full details.
 //
 
+import AVFoundation
 import Foundation
 
 class MediaPlayerProvider: MediaPlayerProviderProtocol {
     private lazy var audioPlayer = AudioPlayer()
     private var audioPlayerStates: [String: AudioPlayerState] = [:]
+    /// Held onto for the duration of the playback, an unowned player is silent.
+    private var soundEffectPlayer: AVAudioPlayer?
     
     var player: AudioPlayerProtocol {
         audioPlayer
@@ -55,6 +58,17 @@ class MediaPlayerProvider: MediaPlayerProviderProtocol {
         }
     }
     
+    /// Doesn't configure an audio session, so that it can be used alongside any existing player or session.
+    func play(soundEffect: SoundEffect) {
+        do {
+            let player = try AVAudioPlayer(contentsOf: soundEffect.fileURL)
+            soundEffectPlayer = player
+            player.play()
+        } catch {
+            MXLog.error("Failed playing the sound effect: \(error)")
+        }
+    }
+    
     // MARK: - Private
     
     private func audioPlayerStateID(for identifier: AudioPlayerStateIdentifier) -> String? {