SystemServer: Manually intiate state transition

Anytime we initiate a transition to `STATE{,_BLE}_TURNING_{ON,OFF}` the
system server is waiting for the Bluetooth app to receive the event,
move to various thread before calling the callback of state transition
back.
By pre-emptively setting the state to the appropriate _TURNING_ state,
we prevent any race condition that could happen meantime

Bug: 351132679
Test: atest ServiceBluetoothTests
Flag: Exempt refactor
Change-Id: Iefe80cc8e4fdc356aa6a6652e2ca73e74b260870