Use become: True when updating /etc/hosts
Use become: True when updating /etc/hosts

Add become: True to update /etc/hosts in pre-install baremetal configuration

TrivialBug
Change-Id: I21e8125272d6b980662779ad55899f04cb6b6a50

dardelean/kolla-ansible,coolsvap/kolla,nihilifer/kolla,openstack/kolla,dardelean/kolla-ansible,rahulunair/kolla,intel-onp/kolla,stackforge/kolla,rahulunair/kolla,GalenMa/kolla,stackforge/kolla,mrangana/kolla,dardelean/kolla-ansible,openstack/kolla,mrangana/kolla,nihilifer/kolla,intel-onp/kolla,stackforge/kolla,coolsvap/kolla,coolsvap/kolla,GalenMa/kolla