first attribute of many proto types is not rendered properly

[tswast]

I'm noticing that often the very first attribute of a proto type is not rendered properly.

https://googleapis.dev/python/bigquerystorage/latest/bigquery_storage_v1beta2/types.html#google.cloud.bigquery_storage_v1beta2.types.AppendRowsResponse.AppendResult

When I look at the source proto, I don't see anything obviously wrong with the formatting there.

https://github.com/googleapis/googleapis/blob/68e5bf3045d7b3ef55f473494a0cd4566491f899/google/cloud/bigquery/storage/v1beta2/storage.proto#L412

But looking at the generated docstring, it's clear that we're missing whitespace between the overall type description and the list of attributes.

https://github.com/googleapis/python-bigquery-storage/blob/d169db3f055d903b25c3aea047ea7d2d58056105/google/cloud/bigquery_storage_v1beta2/types/storage.py#L321-L330

[tswast]

I think this is the relevant template:

gapic-generator-python/gapic/templates/%namespace/%name_%version/%sub/types/_message.py.j2

Lines 2 to 9 in 55e3ef1

	r"""{{ message.meta.doc|rst(indent=4) }}{% if message.fields|length %}
	Attributes:
	{% for field in message.fields.values() %}
	{{ field.name }} ({{ field.ident.sphinx }}):
	{{ field.meta.doc|rst(indent=12, nl=False) }}
	{% endfor %}
	{% endif %}

I thought perhaps that it might just affect nested types, but it does also appear to affect module-level messages.

https://googleapis.dev/python/bigquerystorage/latest/bigquery_storage_v1beta2/types.html#google.cloud.bigquery_storage_v1beta2.types.AvroRows

https://github.com/googleapis/python-bigquery-storage/blob/d169db3f055d903b25c3aea047ea7d2d58056105/google/cloud/bigquery_storage_v1beta2/types/avro.py#L36-L41

[tswast]

Surprisingly, it doesn't happen on all messages. ArrowRecordBatch renders fine.

https://googleapis.dev/python/bigquerystorage/latest/bigquery_storage_v1beta2/types.html#google.cloud.bigquery_storage_v1beta2.types.ArrowRecordBatch

I don't see anything different about the proto docstrings either.

https://github.com/googleapis/googleapis/blob/68e5bf3045d7b3ef55f473494a0cd4566491f899/google/cloud/bigquery/storage/v1beta2/arrow.proto#L35-L39