CLOUDSTACK-8103: Vmsync marks VM as stopped even after failing to stop it in HV
During vmsync if StopCommand (issued as part of PowerOff/PowerMissing report) fails to stop VM (since VM is running on HV),
don't transition VM state to "Stopped" in CS db. Also added a check to throw ConcurrentOperationException if vm state is not
"Running" after start operation.