OOBE: Add gesture navigation screen to list of login screens

Bug: 976949
Change-Id: I076b56bdad13f12b664d41586b143bb238e15c52
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2067720Reviewed-by: Toni Baržić <tbarzic@chromium.org>
Commit-Queue: Matthew Mourgos <mmourgos@chromium.org>
Cr-Commit-Position: refs/heads/master@{#743397}

chrome/browser/resources/chromeos/login/md_login_screens.html

@@ -30,3 +30,5 @@
 <include src="screen_discover.html">
 <include src="screen_marketing_opt_in.html">
 <include src="screen_multidevice_setup.html">
+<gesture-navigation id="gesture-navigation" class="step hidden">
+</gesture-navigation>
\ No newline at end of file