[NAN] Rename to make discovery explicit

Pure rename operation - no other functional changes.

(cherry-pick of commit ddb5f646562f31d7e78778a978e546f85312b009)

Bug: 31470256
Test: unit tests, integrated (sl4a) tests.
Change-Id: I5110d1a673b7ba4e39350d723b5984586fec585a
11 files changed