Add an action name and support 2-pane UI in Backup page

Fix: 377618895
Test: manual, atest UserBackupSettingsActivityTest
Flag: EXEMPT only export activity
Change-Id: If0469a42548a7ba1153dd41f88b68972ce5a23e4

AndroidManifest.xml

@@ -4507,6 +4507,10 @@
                   android:label="@string/privacy_settings_title"
                   android:exported="true"
                   android:icon="@drawable/ic_settings_backup">
+            <intent-filter android:priority="1">
+                <action android:name="com.android.settings.BACKUP_SETTINGS" />
+                <category android:name="android.intent.category.DEFAULT" />
+            </intent-filter>
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
                 <category android:name="android.intent.category.DEFAULT" />

src/com/android/settings/backup/UserBackupSettingsActivity.java

@@ -23,10 +23,10 @@ import android.os.Bundle;
 import android.util.Log;
 
 import androidx.annotation.VisibleForTesting;
-import androidx.fragment.app.FragmentActivity;
 import androidx.fragment.app.FragmentManager;
 
 import com.android.settings.R;
+import com.android.settings.SettingsActivity;
 import com.android.settings.search.BaseSearchIndexProvider;
 import com.android.settingslib.search.Indexable;
 import com.android.settingslib.search.SearchIndexable;
@@ -46,13 +46,16 @@ import java.util.List;
  * Therefore, as a simple workaround, we use a new class which is enabled by default.
  */
 @SearchIndexable
-public class UserBackupSettingsActivity extends FragmentActivity implements Indexable {
+public class UserBackupSettingsActivity extends SettingsActivity implements Indexable {
     private static final String TAG = "BackupSettingsActivity";
     private FragmentManager mFragmentManager;
 
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+        if (isFinishing()) {
+            return;
+        }
 
         BackupSettingsHelper backupHelper = new BackupSettingsHelper(this);