Add NotificationGroupManagerTest

Add some unit tests for NotificationGroupManager testing some basic
functionality and also some of the complex heads up logic.

Bug: 79705024
Test: runtest systemui

Change-Id: I73f01827063d2704a4e1b1d18d479d4e9375447e
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationGroupManager.java b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationGroupManager.java
index 5fe362f..6b6566c 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationGroupManager.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/phone/NotificationGroupManager.java
@@ -415,10 +415,10 @@
             return false;
         }
         NotificationGroup group = mGroupMap.get(getGroupKey(sbn));
-        if (group == null) {
+        if (group == null || group.summary == null) {
             return false;
         }
-        return !group.children.isEmpty();
+        return !group.children.isEmpty() && Objects.equals(group.summary.notification, sbn);
     }
 
     /**