SoftApManager: move interface creation

Move softap interface creation from WifiStateMachine to SoftApManager.
This allows SoftApManager to take full control of the mode and report
errors when attempting to initialize components for the mode.

Bug: 69888789
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Test: manual verification from Settings and QuickSettings
Test: wifi integration tests
Test: wifi CTS tests
Change-Id: Ib6526debdb9b5f376c064b54ca07c3559ffc0d92
7 files changed