[AWARE] Actually shut-down functionality when destroying NAN iface

Destroying the interface doesn't actually execute any functions on
the legacy HAL - i.e. on the HAL side. This may leave state around -
a problem when next "re-enabling" the interface as well as possibly
a power issue.

Add code to actually disable Aware and to destroy interfaces. There
is no need to check on current status since calls will simply fail
quietly if there's nothing to disable and nothing to destroy.

Bug: 62632805
Test: integration non-concurrence test cases NonConcurrencyTest
Change-Id: I11e5bd6f3ed47f6d709ff360c9f4adf5f40234a5