MD Settings: remove previous team members from OWNERS

BUG=388460

Review URL: https://codereview.chromium.org/1710673002

Cr-Commit-Position: refs/heads/master@{#376094}

chrome/browser/chromeos/extensions/users_private/OWNERS

-orenb@chromium.org
+michaelpg@chromium.org
 stevenjb@chromium.org

chrome/browser/extensions/api/autofill_private/OWNERS

-khorimoto@chromium.org
 stevenjb@chromium.org

chrome/browser/extensions/api/passwords_private/OWNERS

-khorimoto@chromium.org
-stevenjb@chromium.org
\ No newline at end of file
+stevenjb@chromium.org

chrome/browser/extensions/api/search_engines_private/OWNERS

-jlklein@chromium.org
-orenb@chromium.org
 stevenjb@chromium.org

chrome/browser/extensions/api/settings_private/OWNERS

-orenb@chromium.org
+michaelpg@chromium.org
 stevenjb@chromium.org