Don't let apps disable the SIM PIN entry screen.

As the user (who controls the app behaviour after all) likely doesn't
see the PIN screen as a lock screen (he likely wants telephony) and the
PIN screen is not shown on a timer-driven basis, it should be treated
specially.

Change-Id: I8d48ab5f097bc926f67eab5835d9b5f1e581db15
Don't recreate keyguard for MCC/MNC changes.

Change-Id: I9e5dfdb12df522dc7dd50c26f35aba26b1bbe44e
Keyguard: Fix configuration change observer

Change I9e5dfdb12df522dc7dd50c26f35aba26b1bbe44e made recreations
only happen when a stored copy of the previous configuration differs
from the current one. But "configuration = otherConfiguration" creates
a reference to the original object, not a copy, so newConfig.diff(mLastConfiguration)
always returned zero. Fixit by creating an actual deep copy of the
Configuration object.

Change-Id: I236932dfc0e121dd83212882b4fe71306c8a3fab