This is a fix to the new change in gate tempest
that creates a shared network so we need to explicitly use
a network in our tests and not relay on choosing the network
automatically
also now we have 2 networks one shared and one public
by default in tempest test in gate so we need to update
the number of default resources
Change-Id: I950501a565c6faf4a7d49ec8a10c683efa05b9ba
9993c6320d