Add a screen to show OEM backup settings.

Moves the backup settings logic to BackupSettingsHelper and
BackupSettingsActivity:
- If the manufacturer provides the intent and the label for their backup
settings in the config.xml, a new intermediate fragment is shown for
Backup settings to let the user pick either standard backup settings or
OEM provided backup settings.
- If config.xml doesn't contain the intent, BackupSettingsActivity is
used as a trampoline activity to launch backup settings provided by the
backup transport of the default backup settings activity, i.e.
PrivacySettingsActivity.

Bug: 34700410
Bug: 33655074
Bug: 33654991
Test: make RunSettingsRoboTests
Change-Id: I78e340fbf926b2a9dc2c4e3942f9337c3c7a933c

src/com/android/settings/search/SearchIndexableResources.java

@@ -37,6 +37,7 @@ import com.android.settings.accounts.UserAndAccountDashboardFragment;
 import com.android.settings.applications.AdvancedAppSettings;
 import com.android.settings.applications.AppAndNotificationDashboardFragment;
 import com.android.settings.applications.SpecialAccessSettings;
+import com.android.settings.backup.BackupSettingsFragment;
 import com.android.settings.bluetooth.BluetoothSettings;
 import com.android.settings.connecteddevice.ConnectedDeviceDashboardFragment;
 import com.android.settings.datausage.DataUsageMeteredSettings;
@@ -156,6 +157,7 @@ public final class SearchIndexableResources {
                 NO_DATA_RES_ID, R.drawable.ic_settings_language);
         addIndex(PhysicalKeyboardFragment.class, NO_DATA_RES_ID, R.drawable.ic_settings_language);
         addIndex(PrivacySettings.class, NO_DATA_RES_ID, R.drawable.ic_settings_backup);
+        addIndex(BackupSettingsFragment.class, NO_DATA_RES_ID, R.drawable.ic_settings_backup);
         addIndex(DateTimeSettings.class, NO_DATA_RES_ID, R.drawable.ic_settings_date_time);
         addIndex(AccessibilitySettings.class, NO_DATA_RES_ID, R.drawable.ic_settings_accessibility);
         addIndex(PrintSettingsFragment.class, NO_DATA_RES_ID, R.drawable.ic_settings_print);