[NAN] Make parcelable class final - per API linter

(cherry-pick of feef60406e961afcda8893c7560382382c358910)

Bug: 31380952
Test: build + sl4a integration test (WifiNanManagerTest:test_nan_discovery_session)
Change-Id: I74c079763d6b3a4f0119b16acd7a18014a10ebbd
3 files changed