WifiStateMachine: switch modes immediately

When switching modes, do it immediately instead of sending a message.
To trigger the transition, moved SET_OPERATIONAL_MODE to be a simple
trigger for the transition.  The states themselves manage the state.

Bug: 78268615
Test: frameworks/opt/net/wifi/tests/wifitests/runtests.sh
Test: manually toggled airplane mode repeatedly (and quickly)
Test: manually toggled wifi repeatedly (and quickly)
Change-Id: I024174c140e610c7d84fc4d42b1dee3487d23b97
2 files changed