kiosk: Fix flaky tests.
- Replace NOTIFICATION_LOGIN_OR_LOCK_WEBUI_VISIBLE with OobeScreenWaiter
on gaia screen because the notification could fire prematurely before
gaia screen is fully loaded;
- Mark device as registered for test so that owner auth UI for network
down cases is consistently shown (instead of occasionally showing gaia);
- Ensure that transitioning to login screen (gaia or account picker) happens
after auto launch app is configured to ensure the warning bubble is
triggered to fix flaky AutolaunchWarning tests;
- Explicit trigger kiosk apps configure reload to ensure
NOTIFICATION_KIOSK_APPS_LOADED is received for EnterpriseKioskApp;
BUG=378358,365507,396320,396334,396336,394032
Review URL: https://codereview.chromium.org/
417823003
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@285937 0039d316-1c4b-4281-b951-d872f2087c98