See https://github.com/googleapis/python-videointelligence/pull/5/files for detailed discussion.

features should be kept as an optional parameter via a synthtool replace until we move to the microgenerator, at which point this can taken with the other breaking changes.

The replacement should have a comment (where appropriate) linking back to this issue so the change is not accidentally merged.