Since the last time the PubSub v1 schema was fetched from Discovery in
April, Google has added new API features: namely, subscription filters
and retry policies. This update to the JSON schema and its generated
code bring in support for these features.
Using `make update-json`, all json descriptions have been update.
Quite interesting to see that there are plenty of new ones which
are giving 404 when queried. An actual bug, or something I should
look into ?