Fix issue #6664140: Time to lock should work even Stay awake...

...in Developer options is on

Don't respect stay awake while on as long as a time to lock limit
is being enforced.  When we start enforcing one, make sure the
setting is off (since we won't be respecting it anyway).

Bug: 6664140
Change-Id: Id07cb528afa0c64c7766341841c51771f507121d