SoftApManager: track iface name

Move handling of the ap interface name in to SoftApManager.  This is
needed to move the ap state change broadcasts in to SApM from
WifiStateMachine.

Bug: 67511330
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Test: integration tests
Test: manual verification of LocalOnlyHotspot functionality
Change-Id: Ief069ca4411aa42645fc68fe7dc9d4155fe3efa6
7 files changed