CLOUDSTACK-9688: Fix failing test_volumes on centos7/kvm
CLOUDSTACK-9688: Fix failing test_volumes on centos7/kvm

Due to OS/hypervisor/environmental configuration, detaching a disk/device
using libvirt can be successful without updating the domain configuration (xml).
This leads to reattachment failure as the device is blocked until the next
reboot. This fixes a specific environment case by performing stop/start on
the VM only in case of KVM, which will recreate a fresh domain config (xml)
as KVM VMs have transient domain configs (xmls don't persist).

Signed-off-by: Rohit Yadav <902b9eb5dd62819678163bd5e00fbf0cbc7c264b@shapeblue.com>

GabrielBrascher/cloudstack,wido/cloudstack,wido/cloudstack,jcshen007/cloudstack,jcshen007/cloudstack,DaanHoogland/cloudstack,wido/cloudstack,GabrielBrascher/cloudstack,jcshen007/cloudstack,resmo/cloudstack,GabrielBrascher/cloudstack,GabrielBrascher/cloudstack,wido/cloudstack,DaanHoogland/cloudstack,DaanHoogland/cloudstack,jcshen007/cloudstack,wido/cloudstack,wido/cloudstack,DaanHoogland/cloudstack,GabrielBrascher/cloudstack,GabrielBrascher/cloudstack,resmo/cloudstack,resmo/cloudstack,DaanHoogland/cloudstack,jcshen007/cloudstack,resmo/cloudstack,DaanHoogland/cloudstack,DaanHoogland/cloudstack,resmo/cloudstack,wido/cloudstack,resmo/cloudstack,GabrielBrascher/cloudstack,jcshen007/cloudstack,jcshen007/cloudstack,resmo/cloudstack