Bugfix UI: Change button text to indicate user network is generating

When network is generating, if the network is not up, we bring the
network up first, then we create the network. During the time we bring
the network up(less than 10s), we change the text as well as the layout
of the button to indicate this process is working.

Signed-off-by: Wen Wang <wenwang@linux.vnet.ibm.com>