Always move Bluetooth Adapter to cold state when turn off Bluetooth.

quick switch feature introduced in ICS does not work very well. Reported
logs indicate the Bluez stack cannot sustain the long time ON/hotoff state.
This change will always move the adapter to code but move it to hotoff
to be able to turn on quickly.
bug 5792792

Change-Id: I41c39d4bf11bb5eb3cd83279e8ec81e01774e008