Improved description of the enable_auto_login_bailout device policy.

BUG=None
R=binzhao@google.com, mnissler@chromium.org

Review URL: https://codereview.chromium.org/143623010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250638 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250638