doc: update CHANGELOG for v2.2.0 release (#9763)

Author: coryan

CHANGELOG.md

@@ -116,7 +116,7 @@ may elicit a deprecation warning. See [#9086] for more details.
 
 </details>
 
-## v2.2.0 - TBD
+## v2.2.0 - 2022-09
 
 ### New Libraries
 
@@ -141,6 +141,21 @@ the APIs in these libraries are stable, and are ready for production use.
 
 </details>
 
+### [Bigtable](/google/cloud/bigtable/README.md)
+
+- fix(bigtable): `DataConnection` refreshes channels ([#9718](https://github.com/googleapis/google-cloud-cpp/pull/9718))
+- fix(bigtable): Use retry policy on all streams with failing mutations ([#9706](https://github.com/googleapis/google-cloud-cpp/pull/9706))
+- feat(bigtable): per-operation Options ([#9627](https://github.com/googleapis/google-cloud-cpp/pull/9627)) ([#9623](https://github.com/googleapis/google-cloud-cpp/pull/9623))
+
+### [Dataproc](/google/cloud/dataproc/README.md)
+
+- feat(dataproc): mark the dataproc services as location dependent ([#9722](https://github.com/googleapis/google-cloud-cpp/pull/9722))
+
+### [Spanner](/google/cloud/spanner/README.md)
+
+- feat(spanner): fine-grained access control ([#9669](https://github.com/googleapis/google-cloud-cpp/pull/9669))
+- feat(spanner): equality for copyable classes ([#9648](https://github.com/googleapis/google-cloud-cpp/pull/9648))
+
 ### [Storage](/google/cloud/storage/README.md)
 
 - We have a new implementation for HTTP requests. This new implementation
@@ -151,6 +166,15 @@ the APIs in these libraries are stable, and are ready for production use.
   `GOOGLE_CLOUD_CPP_STORAGE_USE_LEGACY_HTTP` to any value to use the legacy
   implementation. We are planning to remove the legacy code and the
   `GOOGLE_CLOUD_CPP_STORAGE_USE_LEGACY_HTTP` environment variable by 2022-12.
+- feat(storage): improve error messages on stalled uploads ([#9744](https://github.com/googleapis/google-cloud-cpp/pull/9744))
+- feat(storage): equality for Native IAM types ([#9649](https://github.com/googleapis/google-cloud-cpp/pull/9649))
+- feat(storage): SA credentials default to self-signed JWTs ([#9629](https://github.com/googleapis/google-cloud-cpp/pull/9629))
+
+### [Common Libraries](/google/cloud/README.md)
+
+- feat: group GUAC `Options` in an `OptionsList` ([#9643](https://github.com/googleapis/google-cloud-cpp/pull/9643))
+- fix(rest): cache credentials ([#9620](https://github.com/googleapis/google-cloud-cpp/pull/9620))
+- doc: add table of contents to landing page ([#9671](https://github.com/googleapis/google-cloud-cpp/pull/9671))
 
 ## v2.1.0 - 2022-08