Add Default backup page to list of allowed fragments.

Bug: 75990141
Test: Attempting to invoke ToggleBackupSettingsFragment via XML maifest
changes works.

Change-Id: Idb00fafa998908c8d1c679054cf93c279f60913d
diff --git a/src/com/android/settings/core/gateway/SettingsGateway.java b/src/com/android/settings/core/gateway/SettingsGateway.java
index 0cbc539..dbe8fba 100644
--- a/src/com/android/settings/core/gateway/SettingsGateway.java
+++ b/src/com/android/settings/core/gateway/SettingsGateway.java
@@ -53,6 +53,7 @@
 import com.android.settings.applications.appops.BackgroundCheckSummary;
 import com.android.settings.applications.assist.ManageAssist;
 import com.android.settings.applications.manageapplications.ManageApplications;
+import com.android.settings.backup.ToggleBackupSettingFragment;
 import com.android.settings.bluetooth.BluetoothDeviceDetailsFragment;
 import com.android.settings.bluetooth.BluetoothSettings;
 import com.android.settings.connecteddevice.AdvancedConnectedDeviceDashboardFragment;
@@ -257,6 +258,7 @@
             BluetoothDeviceDetailsFragment.class.getName(),
             DataUsageList.class.getName(),
             DirectoryAccessDetails.class.getName(),
+            ToggleBackupSettingFragment.class.getName(),
     };
 
     public static final String[] SETTINGS_FOR_RESTRICTED = {