The setting to unify work and personal locks is now a toggle,
and therefore always available.
When unifying, if the work lock is sufficient as a device lock
we confirm both locks and set the work lock as the device lock.
If the work lock is not sufficient for the device, the user is
informed and taken to the lock setup flow to set a new unified
lock for both.
Also fix related Strings given UX feedback.
Bug: 26816580
Change-Id: Id019234b0a5ff4462c5f9ba86e53e30981a03e0d
UX requested that we have the settings directly in Security instead
of having a separate screen as implemented previously.
Bug: 26806582
Change-Id: I55c44848621498afe63d3207a52c974c58f9eb78
