chore: release storage 1.20.0 (#5448)

diff --git a/storage/CHANGES.md b/storage/CHANGES.md
index 56c73bf..1e9046b 100644
--- a/storage/CHANGES.md
+++ b/storage/CHANGES.md
@@ -1,6 +1,13 @@
 # Changes
 
 
+## [1.20.0](https://www.github.com/googleapis/google-cloud-go/compare/storage/v1.19.0...storage/v1.20.0) (2022-02-04)
+
+
+### Features
+
+* **storage/internal:** Update definition of RewriteObjectRequest to bring to parity with JSON API support ([#5447](https://www.github.com/googleapis/google-cloud-go/issues/5447)) ([7d175ef](https://www.github.com/googleapis/google-cloud-go/commit/7d175ef12b7b3e75585427f5dd2aab4a175e92d6))
+
 ## [1.19.0](https://www.github.com/googleapis/google-cloud-go/compare/storage/v1.18.2...storage/v1.19.0) (2022-01-25)