The driver start and stop events will be removed as they are now
redundant (and incorrect)
Move to using supplicant INTERFACE_DISABLED indication for deciding
if driver has started or stopped
When driver start is given, the supplicant will first switch to
INTERFACE_DISABLED state and then out of it to start connecting.
We should use this indication to find out driver has started
When driver stop is given, the supplicant will just switch to
INTERFACE_DISABLED state and this indicates driver has stopped
Bug: 4550125
Change-Id: I242cda97951a733c8707c8d99cdfcc9a33b75c2d
1523da22e9