Null check message stack for the specific id before effectively replying the message

app/src/main/java/chat/rocket/android/push/PushManager.kt

@@ -441,28 +441,29 @@ object PushManager {
                 val message: CharSequence? = extractMessage(intent)
                 val pushMessage = intent?.extras?.getSerializable("push") as PushMessage?
 
-                if (pushMessage != null) {
-                    val singleNotId = pushMessage.notificationId.toInt()
+                pushMessage?.let {
+                    val userNotId = pushMessage.notificationId.toInt()
                     val groupTuple = groupMap.get(pushMessage.host)
-                    for (msg in messageStack[singleNotId]) {
-                        manager.cancel(singleNotId)
+                    messageStack[userNotId]?.let {
+                        for (msg in messageStack[userNotId]) {
+                            manager.cancel(userNotId)
                             groupTuple?.second?.decrementAndGet()
-                        println("Decremented")
                         }
-                    clearMessageBundle(singleNotId)
-                    if (groupTuple != null) {
+                        clearMessageBundle(userNotId)
+                        groupTuple?.let {
                             val groupNotId = groupTuple.first
                             val totalNot = groupTuple.second.get()
                             if (totalNot == 0) {
                                 manager.cancel(groupNotId)
                             }
                         }
-                    if (message != null) {
+                        message?.let {
                             sendMessage(context, message, pushMessage.rid)
                         }
                     }
                 }
             }
+        }
 
         private fun extractMessage(intent: Intent?): CharSequence? {
             val remoteInput: Bundle? =