Not a blocking comment - just a way to shorten this function in either this PR or another future one.

It looks like the execution and assertion parts are the same, so maybe that can be executed either way with the policy id, and the code can look something like:

    if policy_id is None:
          policy_id = self.autoscale_behaviors.get_policy_properties(group.scalingPolicies)['id']

    <execute and assert here>