Populate recent notifying apps from usage events

Which is the data source that the screen this widget
links to uses

Test: robotests
Fixes: 131641848
Change-Id: I02ce178823e72b3b3606ad4f7110587b6dc0afe3

src/com/android/settings/notification/NotificationBackend.java

@@ -312,15 +312,6 @@ public class NotificationBackend {
         }
     }
 
-    public List<NotifyingApp> getRecentApps() {
-        try {
-            return sINM.getRecentNotifyingAppsForUser(UserHandle.myUserId()).getList();
-        } catch (Exception e) {
-            Log.w(TAG, "Error calling NoMan", e);
-            return new ArrayList<>();
-        }
-    }
-
     public int getBlockedAppCount() {
         try {
             return sINM.getBlockedAppCount(UserHandle.myUserId());