[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 84cfbd62d01cd70470eddbcb3edb34cf9cc733d5)

Bug: 31470256
Test: integration (sl4a) tests
Change-Id: I9be791c1d23cbcec4123e6fa8b52e42461641530
1 file changed
tree: 99d30a1af1fd3af39054d5cce1b1dc512160f735
  1. acts/