As become is applied to most of the tasks in the role, let's remove
them and suggest applying become on the playbook level instead.
We do not have become applied on task level in any other managed
role.
This also helps to workaround PAM/apparmor issue with CentOS
in Docker for molecule test.
We also deal with an intermittent failures in Docker, as interface
naming/ordering is random and non-deterministic with no way of
controlling it.
Thus, instead of detecting an IP address by interface, we hardcode the
IP address both for containers and in FRR configurations.
Change-Id: I73471dd895eea5c6abfbec24681c796d5e7d813d
970fab180c