[NAN] Change Broadcast for NAN status change to notification only [DO NOT MERGE]

Remove information about current status of NAN. Receiver will have
to query that information explicitly. New pattern (per API council
review) - helps reduce window for having old information.

Bug: 31470256
Test: unit tests & integration (sl4a) tests.
Change-Id: Ie197e1be71ec04dfbf65cf29e64c0cd3fa7c5190