ChromeVox focus not properly shown when navigating

If you navigate to "Manage what you sync" page and then back,
the arrow pointing back to "Manage what you sync" is not highlighted
when in ChromeVox mode

Steps:
1. People
2. Sync and Google Services
3. Manage what you sync
4. Back button

Bug: 1029954
Test: Manual
Change-Id: I92fc08efdb1f2ea5f1e06232e08df23ab6f03910
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2488603
Auto-Submit: Michael Irani <michaelirani@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#819142}

chrome/browser/resources/settings/chromeos/os_people_page/os_people_page.html

@@ -149,7 +149,8 @@
             learn-more-url="$i18n{syncAndGoogleServicesLearnMoreURL}">
           <settings-sync-page
               sync-status="[[syncStatus]]" prefs="{{prefs}}"
-              page-visibility="[[pageVisibility.privacy]]">
+              page-visibility="[[pageVisibility.privacy]]"
+              focus-config="[[focusConfig_]]">
           </settings-sync-page>
         </settings-subpage>
       </template>