fix: suppress stale push notifications for active chats

fix: clear existing chat notifications when FCM arrives for an already open conversation

android/app/src/main/java/ru/daemonlord/messenger/push/MessengerFirebaseMessagingService.kt

@@ -23,6 +23,7 @@ class MessengerFirebaseMessagingService : FirebaseMessagingService() {
     override fun onMessageReceived(message: RemoteMessage) {
         val payload = PushPayloadParser.parse(message) ?: return
         if (activeChatTracker.activeChatId.value == payload.chatId) {
+            notificationDispatcher.clearChatNotifications(payload.chatId)
             return
         }
         notificationDispatcher.showChatMessage(payload)