Fix some minor Spaces method visibility issues

Summary: Ref T8377. These were picked up by tests.

Test Plan: `arc unit --everything`

Reviewers: btrahan

Reviewed By: btrahan

Subscribers: epriestley

Maniphest Tasks: T8377

Differential Revision: https://secure.phabricator.com/D13130

src/applications/spaces/controller/PhabricatorSpacesListController.php

@@ -32,7 +32,7 @@ final class PhabricatorSpacesListController
     return $nav;
   }
 
-  public function buildApplicationCrumbs() {
+  protected function buildApplicationCrumbs() {
     $crumbs = parent::buildApplicationCrumbs();
 
     $can_create = $this->hasApplicationCapability(

src/applications/spaces/query/PhabricatorSpacesNamespaceSearchEngine.php

@@ -31,7 +31,7 @@ final class PhabricatorSpacesNamespaceSearchEngine
     return '/spaces/'.$path;
   }
 
-  public function getBuiltinQueryNames() {
+  protected function getBuiltinQueryNames() {
     $names = array(
       'all' => pht('All Spaces'),
     );

src/applications/spaces/storage/PhabricatorSpacesNamespace.php

@@ -29,7 +29,7 @@ final class PhabricatorSpacesNamespace
       ->setEditPolicy($edit_policy);
   }
 
-  public function getConfiguration() {
+  protected function getConfiguration() {
     return array(
       self::CONFIG_AUX_PHID => true,
       self::CONFIG_COLUMN_SCHEMA => array(