installer:show close button when without wm;check is virtualMachine

tower:https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/a928d94d50694f93a5b51eee3fa0680a/
tower:https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/d41c16731aaa400f809df44cdcb34f30/#a562f90d83a8403a85036fe8020481e0
Change-Id: I7dd945ab0e597d87302dd2c50eb350c27b6d9d7a