Fix notification display order.

Messages in notifications were showing in reverse order,
that is newest on top instead of newest at the bottom making
multiple messages hard to read.

Closes #1984

src/org/thoughtcrime/securesms/notifications/MessageNotifier.java

@@ -53,6 +53,7 @@ import org.whispersystems.textsecure.api.messages.TextSecureEnvelope;
 
 import java.io.IOException;
 import java.util.List;
+import java.util.ListIterator;
 
 /**
  * Handles posting system notifications for new messages.
@@ -180,7 +181,9 @@ public class MessageNotifier {
 
     SpannableStringBuilder content = new SpannableStringBuilder();
 
-    for (NotificationItem item : notifications) {
+    ListIterator<NotificationItem> iterator = notifications.listIterator(notifications.size());
+    while(iterator.hasPrevious()) {
+      NotificationItem item = iterator.previous();
       content.append(item.getBigStyleSummary());
       content.append('\n');
     }
@@ -224,7 +227,9 @@ public class MessageNotifier {
 
     InboxStyle style = new InboxStyle();
 
-    for (NotificationItem item : notifications) {
+    ListIterator<NotificationItem> iterator = notifications.listIterator(notifications.size());
+    while(iterator.hasPrevious()) {
+      NotificationItem item = iterator.previous();
       style.addLine(item.getTickerText());
     }