Fix double reboot issue during soft reboot

Using the ID of domain in Libvirt to recognize the hard reboot has been
implemented or not, if the ID changed, we believe the domain has been rebooted,
return True and break from soft reboot.

Fixes: bug #1046356

Change-Id: Iec2f9e8225cfe2779f84d2095667f3c0e621e935
(cherry picked from commit 6344bff494758e0d7d7d25f43a3b56d82447441e)
Merge "Fix double reboot issue during soft reboot" into stable/folsom