Add notification not showing debuglog.

app/src/main/java/org/thoughtcrime/securesms/notifications/v2/MessageNotifierV2.kt

@@ -222,6 +222,14 @@ class MessageNotifierV2(context: Application) : MessageNotifier {
     SignalDatabase.mmsSms.setNotifiedTimestamp(System.currentTimeMillis(), smsIds, mmsIds)
 
     Log.i(TAG, "threads: ${state.threadCount} messages: ${state.messageCount}")
+
+    if (Build.VERSION.SDK_INT >= 24) {
+      val ids = state.notificationIds + stickyThreads.map { (_, stickyThread) -> stickyThread.notificationId }
+      val notShown = ids - ServiceUtil.getNotificationManager(context).getDisplayedNotificationIds().getOrDefault(emptySet())
+      if (notShown.isNotEmpty()) {
+        Log.e(TAG, "Notifications should be showing but are not for ${notShown.size} threads")
+      }
+    }
   }
 
   override fun clearReminder(context: Context) {