Vagrant

Of the learning environments that leverage Ansible, very few are using roles. This can make porting Ansible playbooks across learning environments more difficult. To fix this, Ansible-using learning environments need to be refactored (where possible) to use an Ansible role.

Since #6008, subscriberdb moved to SubscriberDBCloudClient class to fetch the subscriberdb data from Orchestrator, and SubscriberDBStreamerCallback was deprecated.

There are multiple references to the deprecated class (mainly on unit tests) that can be removed as this class it's not used anymore.

Unit tests reference: `lte/gateway/python/magma/subscriberdb/tests/streamer_callback_tests.p

Some old programs versions can be found here if someone needs them to test old exploits for instance.