kiosk: Show network screen for interrupted enrollment.

http://crbug.com/322666 makes enrollment screen to be the first
screen for an interrupted auto start enrollment flow (remora). But
the enrollment screen does not handle flaky network well and often
lands user in a network error page. This CL makes the interrupted
flow resumes from network screen.

BUG=332572

Review URL: https://codereview.chromium.org/131463005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244115 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 244115