Use User Preference for logged-in HTTPS choice

Use the user's preference, instead of the login-form checkbox, to
decide if the session cookies should be setup for HTTPS only.

Relies on core patch: I69e9cb23b8d700e821b8a961c672958e4e19e4f8

Change-Id: Ic7be49787f3ba0a1331081206c96ef7b67493b0d
Merge "Use User Preference for logged-in HTTPS choice"