xci: roles: configure-network: Wait for connection when configuring the network

xci: roles: configure-network: Wait for connection when configuring the network

Ansible some times loses connection with the host after we configure its
network interface. This shouldn't happen since the host is actually up
and running. As a result of which, we need to fire-and-forget the
restart of the network service and then try to reach the SSH port. We
also need to make sure that all required packages are installed.
Finally, we drop the 'ignore_errors' parameter since we really need to
know when the networking configuration has failed.

Change-Id: I366192737b5c4e01964eaf187396eababbdc808e
Signed-off-by: Markos Chandras <mchandras@suse.de>