Camera: Add support for notifying NFC stack when camera is active

On some devices, NFC full poll operation and camera operation
interfere.  Add a system property ro.camera.notify_nfc.  When set to >
0, the NFC adapter will be notified to disable polling whenever the
camera is active.

Bug: 23393557
Change-Id: I7e22018900970cbbd3d34bd8b3974e0b1cc98a8d