Add filtering to notification channel settings

Allow apps that are launching this page to specify targeted subsets of
settings that should be shown.

Test: settings notification robotests
Bug: 177246841
Change-Id: Ib491c43f1861a9775e3b25f39134cdbe105a7ff8

src/com/android/settings/notification/app/ConversationDemotePreferenceController.java

@@ -16,6 +16,7 @@
 
 package com.android.settings.notification.app;
 
+import android.app.NotificationChannel;
 import android.content.Context;
 import android.text.TextUtils;
 
@@ -56,6 +57,11 @@ public class ConversationDemotePreferenceController extends NotificationPreferen
         return !TextUtils.isEmpty(mChannel.getConversationId()) && !mChannel.isDemoted();
     }
 
+    @Override
+    boolean isIncludedInFilter() {
+        return mPreferenceFilter.contains(NotificationChannel.EDIT_CONVERSATION);
+    }
+
     public void updateState(Preference preference) {
         preference.setEnabled(mAdmin == null);
     }