title: Android notification does not light up screen
body: <p>I'm creating an android app using notifications.</p>
  <p>My problem is that when one comes in while the screen is turned off it won't turn on.</p>
  <p><strong>This is my notification channel:</strong></p>
  <pre><code>    val channel = NotificationChannel(
      getString(R.string.notification_channel),
      &quot;Notification Channel&quot;,
      NotificationManager.IMPORTANCE_HIGH
          )
      channel.enableVibration(true)
      channel.apply { description = &quot;Reminders&quot; }
  </code></pre>
  <p><strong>This is my alarm manager:</strong></p>
  <pre><code>val pendingIntent =
  PendingIntent.getBroadcast(context, notificationRequestCode, intent, 0)
  
  val alarmManager = context.getSystemService(Context.ALARM_SERVICE) as AlarmManager
  
  alarmManager.setExactAndAllowWhileIdle(
      AlarmManager.RTC_WAKEUP,
      notificationMillis,
      pendingIntent
  )
  </code></pre>
  <p><strong>My intent works with a broadcast receiver from where the notification is created.
  This is it:</strong></p>
  <pre><code>val notification =
          Notification.Builder(
              callingContext,
              callingContext.getString(R.string.notification_channel)
          ).setSmallIcon(R.drawable.access_time_24px)
              .setContentTitle(notificationTitle).setContentText(notificationText)
              .setStyle(Notification.BigTextStyle().bigText(notificationText))
              .setContentIntent(notificationClickPendingIntent)
              .setShowWhen(true)
              .setAutoCancel(true)
      with(NotificationManagerCompat.from(callingContext)) {
          notify(currentChannel, notification.build())
      }
  </code></pre>
  <p>I haven't found any documentation explicitly describing how to handle this.
  RTC_WAKEUP, high priority and allowWhileIdle all don't seem to work.</p>
  <p>Any help would be greatly appreciated.</p>