title: Notifications are not working with kotlin
body: <p>I'm trying to send a local notification when a user reaches a specific phase in the android application built with kotlin. </p>
  
  <p>Here is the code I'm using : </p>
  
  <pre><code>
      override fun onCreate(savedInstanceState: Bundle?) {
          super.onCreate(savedInstanceState)
          pageViewModel = ViewModelProviders.of(this).get(PageViewModel::class.java).apply {
              setIndex(arguments?.getInt(ARG_SECTION_NUMBER) ?: 1)
          }
      }
  
      override fun onCreateView(
          inflater: LayoutInflater, container: ViewGroup?,
          savedInstanceState: Bundle?
      ): View? {
          activity?.let {
              Mapbox.getInstance(
                  it,
                  getString(R.string.mapbox_access_token2)
              )
          }
          val root =
              inflater.inflate(R.layout.fragment_navigation, container, false)
          return root
      }
  
      override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
          super.onViewCreated(view, savedInstanceState)
          mapView.onCreate(savedInstanceState)
          mapView.getMapAsync(this)
          startTripNotification()
      }
  
      private fun startTripNotification() {
          val pendingIntent = PendingIntent.getActivity(activity, 0, Intent(), 0)
          val     notification = Notification.Builder(activity)
              .setContentTitle("test notification title")
              .setContentText("test notification text")
              .setSmallIcon(R.mipmap.ic_main_icon_round)
              .setLargeIcon(BitmapFactory.decodeResource(this.resources, R.mipmap.ic_launcher))
          notification.setContentIntent(pendingIntent)
          val notificationManager = activity?.getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager
          notificationManager.notify(0, notification.build())
      }
  </code></pre>
  
  <p>There is no response at all, using Debugging I found out that the function <code>startTripNotification</code> is being triggered correctly, but still no notification appears or any response, even in the <code>logCat</code> nothing being added at all.</p>