Docs build in google-cloud-enterpriseknowledgegraph fails with Bullet list ends without a blank line; unexpected unindent.

[parthea]

I had to manually fix a google-cloud-python PR that had a comment looking like this:

        Attributes:
            enable_geocoding_separation (bool):
                If true, separate clusters by their
                geographic region (from geocoding). Uses the
                following entity features:

                - schema.org/addressLocality
                - schema.org/addressRegion
                - schema.org/addressCountry
                Warning: processing will no longer be
                regionalized!

The issue is that sphinx expects a new line after list items.

Sphinx expects this:

        Attributes:
            enable_geocoding_separation (bool):
                If true, separate clusters by their
                geographic region (from geocoding). Uses the
                following entity features:

                - schema.org/addressLocality
                - schema.org/addressRegion
                - schema.org/addressCountry
  
                Warning: processing will no longer be
                regionalized!

We should add this as a test here and also consider proposing an update to AIPs to check if the API protos could follow this convention as well.