Add API "startSubsystemRestart" and callback function

In order to trigger subsystem restart to reload wlan firmware,
this change adds an API for framework and vendor HAL.
Meanwhile, create new callback function for subsystem restart instead of
 general callback "onFailure()".

Bug: 178126071
Test: vendor HAL can received API call
      subsystem restart will callback "onSubsystemRestart()"

Change-Id: If3dc84049a9171677ad281c9bcc67a44dc722bdb