Settings: remove multiple users search when multi-user not supported

When multi-user feature not supported in framework, SettingsIntelligence should not build the index of multiple users for searching.

Return empty list when multi-user feature not supported during building search index.

Change-Id: Id2fb8f2066784d63bbfd5c396da88b04306a3563
Bug: 310108420

src/com/android/settings/users/UserSettings.java

@@ -1719,6 +1719,9 @@ public class UserSettings extends SettingsPreferenceFragment
                 public List<SearchIndexableRaw> getRawDataToIndex(Context context,
                         boolean enabled) {
                     final List<SearchIndexableRaw> rawData = new ArrayList<>();
+                    if (!UserManager.supportsMultipleUsers()) {
+                        return rawData;
+                    }
 
                     SearchIndexableRaw allowMultipleUsersResult = new SearchIndexableRaw(context);