ClientModeManager: control WifiStateMachine

Move control of WifiStateMachine from WifiController over to
ClientModeManager.

Note: this CL removes supplicant detection for iface down events.

Bug: 31346104
Test: manually toggled between modes
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Test: wifi integration tests
Change-Id: Ieed3609af529ab65c19b48999fb7543212be458c
11 files changed