[AWARE] Add data-path security configuration (PMK)

Add API to optionally provide a pairwise master key (PMK)
to configure security on a data-path.

Clarify the default API to mean open (unencrypted) data-path.

Bug: 33552694
Test: unit tests and integration (sl4a) tests
Change-Id: I43fe704547f2921b3207f215e42d253837aa04e9