[NAN] Refactor WifiNanManager to create separate sessions per connect.

Separate session enables separate namespace for functions which depend
on a connection to exist.

(cherry-pick of commit 471025fa5ecbb3eaedd22e249f16e91fecaf3494)

Bug: 31470256
Test: unit tests
Change-Id: I9d043f53adbba4044db4ffb1f7045ae78d75fb8b
6 files changed
tree: 9aed0aa2674264465aad2920cb8e90068a8fefa0
  1. service/
  2. PREUPLOAD.cfg