Release PubSub 1.0.0 (googleapis#9145)

* Release 1.0.0

* Update CPS Python library READMEs to indicate the library is now GA. Also add some extra notes about versioning and contributions.

* Fix badge image

* Fix rst docs

* Address comments by Peter and Bu Sun

* Update repo metadata

* Improve changelog entry

Release bigtable 1.0.0 (googleapis#9140)

* Release bigtable 1.0.0

Release storage 1.19.0 (googleapis#9138)

Release automl 0.5.0 (googleapis#9141)

Release 0.2.1 (googleapis#9093)

Release error_reporting 0.32.1 (googleapis#9094)

Release vision 0.39.0 (googleapis#9017)

* Release 0.39.0

* Fix typo.

Release videointelligence 1.11.0 (googleapis#9018)

Release trace 0.22.1 (googleapis#9013)

Release tasks 1.2.1 (googleapis#9012)

* Release 1.2.1

* Adjust changelog grouping.