Update with session mode fix

This closes #607

crates/apps/metronome/ios/Runner/AppDelegate.swift

@@ -1,5 +1,16 @@
 import UIKit
 import Flutter
+import AVFAudio
+
+func configureAudioSession() {
+  let audioSession = AVAudioSession.sharedInstance()
+  do {
+    // Set the audio session category and mode.
+    try audioSession.setCategory(.playback, mode: .default, options: [.mixWithOthers])
+  } catch {
+    print("Failed to set the audio session configuration")
+  }
+}
 
 @UIApplicationMain
 @objc class AppDelegate: FlutterAppDelegate {
@@ -9,6 +20,9 @@ import Flutter
   ) -> Bool {
     let value = dummy_method_to_enforce_bundling()
     print(value)
+
+    configureAudioSession()
+
     GeneratedPluginRegistrant.register(with: self)
     return super.application(application, didFinishLaunchingWithOptions: launchOptions)
   }