Prevent crash in Search from Stack overflow

NotificationSettingBase's getPreferenceController call
is recursive with no base case which crashes search.

Root cause here is that NotificationSettingsBase should
not be indexed for seacrh but was probably failing the
code inspection test. Added NotificationSettingsBase
child classes to grandfather list of classes that
should be ignored for search.

Change-Id: I04ed242db3a394b88e0d0ac420aaaff6f9301cb5
Fixes: 69096424
Test: robotests

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

@@ -163,15 +163,4 @@ public class ChannelImportanceSettings extends NotificationSettingsBase
         mChannel.lockFields(USER_LOCKED_IMPORTANCE);
         mBackend.updateChannel(mAppRow.pkg, mAppRow.uid, mChannel);
     }
-
-    // This page exists per notification channel; should not be included
-    // in search
-    public static final SearchIndexProvider SEARCH_INDEX_DATA_PROVIDER =
-            new BaseSearchIndexProvider() {
-                @Override
-                public List<SearchIndexableResource> getXmlResourcesToIndex(
-                        Context context, boolean enabled) {
-                    return null;
-                }
-            };
 }