Add PendingIntent.FLAG_UPDATE_CURRENT to action button intents

Without it, if the hashCodes matches a button from one of the previous notifications, the pending intent won't be updated, and it may perform an action from the old message.

Author: vbabenkoru

iterableapi/src/main/java/com/iterable/iterableapi/IterableNotificationBuilder.java

@@ -119,7 +119,7 @@ public void createNotificationActionButton(Context context, IterableNotification
         buttonIntent.putExtra(IterableConstants.ACTION_IDENTIFIER, button.identifier);
 
         PendingIntent pendingButtonIntent = PendingIntent.getBroadcast(context, buttonIntent.hashCode(),
-                buttonIntent, 0);
+                buttonIntent, PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE);
 
         NotificationCompat.Action.Builder actionBuilder = new NotificationCompat.Action
                 .Builder(NotificationCompat.BADGE_ICON_NONE, button.title, pendingButtonIntent);