fix: iOS build

ios/Runner/AppDelegate.swift

@@ -8,6 +8,9 @@ import Flutter
     didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?
   ) -> Bool {
     GeneratedPluginRegistrant.register(with: self)
+    if #available(iOS 10.0, *) {
+      UNUserNotificationCenter.current().delegate = self as? UNUserNotificationCenterDelegate
+    }
     return super.application(application, didFinishLaunchingWithOptions: launchOptions)
   }
 }

ios/Runner/Info.plist

@@ -31,6 +31,7 @@
 	<key>UIBackgroundModes</key>
 	<array>
 		<string>audio</string>
+		<string>remote-notification</string>
 	</array>
 	<key>UILaunchStoryboardName</key>
 	<string>LaunchScreen</string>