Enhance BT On scenario in power off

Enhance BT On scenario in power off

[Problem] BT is not turned on when flight mode is unset during power
 off. This is not usual case but it happens sometimes in wearable model.
 Specific case is described in "Checking Method".
[Cause & Measure] If BT on is requested during power off, just update
 vconf of bt state. So that in next boot, BT is turned on.
[Checking Method] BT On -> Cool down (LimitAction) / Flight mode on ->
 BT Off -> Cool down (ShutDown) -> Flight mode off -> BT On, but it's not done
 -> Power off -> Power On -> BT should be turned on

Change-Id: I63775e38b09b77d7eb7c4cf9ae8e8445902b793a