Several docs builds failing with unexpected indentation

[parthea]

See build log here which shows several docs build failures with error message unexpected indentation. The issue is that sphinx expects a new line before a list, and most protos do not have this new line. For example, see this error below

sphinx.errors.SphinxWarning: /home/runner/work/google-cloud-python/google-cloud-python/packages/google-cloud-advisorynotifications/google/cloud/advisorynotifications_v1/types/service.py:docstring of google.cloud.advisorynotifications_v1.types.service.LocalizationState:10:Unexpected indentation.

https://github.com/googleapis/googleapis-gen/blob/52c83f985d3fe2c248378988aee6fda6606f9ef3/google/cloud/advisorynotifications/v1/advisorynotifications-v1-py/google/cloud/advisorynotifications_v1/types/service.py#L72

We have

            Localization is not applicable for requested
            language. This can happen when:
            - The requested language was not supported by
              Advisory Notifications at the time of
              localization (including notifications created
              before the localization feature was launched).
            - The requested language is English, so only the
              English text is returned.

but sphinx expects an additional line after the colon

            Localization is not applicable for requested
            language. This can happen when:

            - The requested language was not supported by
              Advisory Notifications at the time of
              localization (including notifications created
              before the localization feature was launched).
            - The requested language is English, so only the
              English text is returned.