Changing the ordering for heads up notifications

In the new ranking, notifications with fullscreen
intents always take priority over those without,
such that when you get a call and a message
in succession, you would always see the
call on top and are able to pick it up.

Bug: 22778349
Change-Id: Ia9aaf009998fc9493f513dc71f2649d38ccf7a79
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/policy/HeadsUpManager.java b/packages/SystemUI/src/com/android/systemui/statusbar/policy/HeadsUpManager.java
index 299f20e..4a95d3a 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/policy/HeadsUpManager.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/policy/HeadsUpManager.java
@@ -582,6 +582,13 @@
 
         @Override
         public int compareTo(HeadsUpEntry o) {
+            boolean selfFullscreen = hasFullScreenIntent(entry);
+            boolean otherFullscreen = hasFullScreenIntent(o.entry);
+            if (selfFullscreen && !otherFullscreen) {
+                return -1;
+            } else if (!selfFullscreen && otherFullscreen) {
+                return 1;
+            }
             return postTime < o.postTime ? 1
                     : postTime == o.postTime ? entry.key.compareTo(o.entry.key)
                             : -1;