NFC: getNdefMessage() should throw exception if no tag in field.

According to documentation, an TagLostException should be thrown, if
the tag has been moved out of field when reading NDEF message.

Change-Id: Ib7e485ed442027fdebd5bc7a46101fbca0c88bdb
Don't recreate keyguard for MCC/MNC changes.

Change-Id: I9e5dfdb12df522dc7dd50c26f35aba26b1bbe44e
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
SystemUI: Set Status bar opaque during drawer pulldown on tablets only

The status bar only needs to be set as opaque when the notification
drawer is pulled down on 600dp and 720dp devices. On phones, this
is unnecessary as the top header of the drawer covers the status
bar on the phone UI. This change makes a huge difference in
reponsiveness on devices that run the phone UI as there is no
longer a delay before the drawer appears when interacting with it
on an activity with transclucent window decor.

Patch Set 3: Fix formatting, adjust comment
Patch Set 5: Delete file derp

Change-Id: I932bb92a5245f0323d3317776efbdc9151db449d