fix: show notification_missed_call localized string

Author: cybex-dev

ios/Classes/SwiftTwilioVoicePlugin.swift

@@ -683,6 +683,7 @@ public class SwiftTwilioVoicePlugin: NSObject, FlutterPlugin,  FlutterStreamHand
 
             let title = userName ?? self.clients["defaultCaller"] ?? self.defaultCaller
             content.title = title
+            content.body = NSLocalizedString("notification_missed_call_body", comment: "")
 
             let trigger = UNTimeIntervalNotificationTrigger(timeInterval: 1, repeats: false)
             let request = UNNotificationRequest(identifier: UUID().uuidString,