Experiment: hide unused channels in settings

behind a 3-dot menu. "unused" in this case means a channel that is not blocked but also hasn't sent a notification in the last 2 weeks

Test: manual
Flag: com.android.server.notification.notification_hide_unused_channels
Bug: 322536537
Change-Id: I99f5a61411c9b3a567fd7517f0bf7ea33bb7637c

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

@@ -272,6 +272,16 @@ public class NotificationBackend {
         }
     }
 
+    public ParceledListSlice<NotificationChannelGroup> getGroupsWithRecentBlockedFilter(String pkg,
+            int uid) {
+        try {
+            return sINM.getRecentBlockedNotificationChannelGroupsForPackage(pkg, uid);
+        } catch (Exception e) {
+            Log.w(TAG, "Error calling NoMan", e);
+            return ParceledListSlice.emptyList();
+        }
+    }
+
     public ParceledListSlice<ConversationChannelWrapper> getConversations(String pkg, int uid) {
         try {
             return sINM.getConversationsForPackage(pkg, uid);