Create router and dhcp when create_default_network set

We are trying to make server SSH-able before detach volume
is performed (details in bug mentioned below). Creating
router and dhcp is needed to setup the proper network path
for server otherwise it fail
- https://zuul.opendev.org/t/openstack/build/04e11a0eac12447f8a3c47fb385b0753

Related-Bug: #1960346

Change-Id: I18eff5a4216d5683a5d49ad0e400ac663650e7a9
1 file changed