Use different CIDRs for private and public subnets

In test "test_connectivity_dvr_and_no_dvr_routers_in_same_subnet", as
reported in the bug, the public IP (floating IP) and the private IP
are in the same CIDR. This breaks the isolation between networks.

Co-Authored-By: Rodolfo Alonso Hernandez <ralonsoh@redhat.com>

Closes-Bug: #1861282

Change-Id: I39ca6474068d2e169dff1b81d2a0c71a8361c01f
2 files changed