CA-270408: Refine add child node order in AttachUsbDialog
CA-270408: Refine add child node order in AttachUsbDialog

Signed-off-by: Kun Ma <a0654752d70750c00d9512cb63e32ec4c279acb7@citrix.com>

minli1/xenadmin,MihaelaStoica/xenadmin,jijiang/xenadmin,MihaelaStoica/xenadmin,kc284/xenadmin,jijiang/xenadmin,xenserver/xenadmin,minli1/xenadmin,MihaelaStoica/xenadmin,jijiang/xenadmin,jijiang/xenadmin,stephen-turner/xenadmin,MihaelaStoica/xenadmin,kc284/xenadmin,jijiang/xenadmin,xenserver/xenadmin,kc284/xenadmin,kc284/xenadmin,kc284/xenadmin,jijiang/xenadmin,minli1/xenadmin,stephen-turner/xenadmin,stephen-turner/xenadmin,stephen-turner/xenadmin,MihaelaStoica/xenadmin,minli1/xenadmin,xenserver/xenadmin,stephen-turner/xenadmin,minli1/xenadmin,minli1/xenadmin,MihaelaStoica/xenadmin,stephen-turner/xenadmin