Rename os_advanced_page_browsertest.js to os_settings_page_test.js

It's testing the os-settings-page element, so rename it to match.

This is a prelude to trying to de-flake it, then adding more tests to
it.

TBR=hsuregan@chromium.org

Bug: 967896
Change-Id: I240124bd18169bb7126241416ce7e1a5cce03361
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1828107Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: James Cook <jamescook@chromium.org>
Cr-Commit-Position: refs/heads/master@{#700466}

chrome/test/data/webui/settings/chromeos/os_settings_browsertest.js

@@ -100,20 +100,20 @@ TEST_F('OSSettingsAddUsersTest', 'AllJsTests', () => {
   mocha.run();
 });
 
-// Tests for the advanced page browser tests.
+// Tests for the main contents of the settings page.
 // eslint-disable-next-line no-var
-var OSSettingsAdvancedPageBrowserTest = class extends OSSettingsBrowserTest {
+var OSSettingsPageTest = class extends OSSettingsBrowserTest {
   /** @override */
   get extraLibraries() {
     return super.extraLibraries.concat([
       BROWSER_SETTINGS_PATH + '../test_util.js',
-      'os_advanced_page_browsertest.js',
+      'os_settings_page_test.js',
     ]);
   }
 };
 
 // Disabled due to flakiness on linux-chromeos-rel. https://crbug.com/992116
-TEST_F('OSSettingsAdvancedPageBrowserTest', 'DISABLED_AllJsTests', () => {
+TEST_F('OSSettingsPageTest', 'DISABLED_AllJsTests', () => {
   // Run all registered tests.
   mocha.run();
 });