chore: release storage 1.18.0 (#4951)

diff --git a/storage/CHANGES.md b/storage/CHANGES.md
index 38ca4f8..f0dbf92 100644
--- a/storage/CHANGES.md
+++ b/storage/CHANGES.md
@@ -1,5 +1,18 @@
 # Changes
 
+## [1.18.0](https://www.github.com/googleapis/google-cloud-go/compare/storage/v1.17.0...storage/v1.18.0) (2021-10-11)
+
+
+### Features
+
+* **storage:** returned wrapped error for timeouts ([#4802](https://www.github.com/googleapis/google-cloud-go/issues/4802)) ([0e102a3](https://www.github.com/googleapis/google-cloud-go/commit/0e102a385dc67a06f6b444b3a93e6998428529be)), refs [#4197](https://www.github.com/googleapis/google-cloud-go/issues/4197)
+* **storage:** SignedUrl can use existing creds to authenticate ([#4604](https://www.github.com/googleapis/google-cloud-go/issues/4604)) ([b824c89](https://www.github.com/googleapis/google-cloud-go/commit/b824c897e6941270747b612f6d36a8d6ae081315))
+
+
+### Bug Fixes
+
+* **storage:** update PAP to use inherited instead of unspecified ([#4909](https://www.github.com/googleapis/google-cloud-go/issues/4909)) ([dac26b1](https://www.github.com/googleapis/google-cloud-go/commit/dac26b1af2f2972f12775341173bcc5f982438b8))
+
 ## [1.17.0](https://www.github.com/googleapis/google-cloud-go/compare/storage/v1.16.1...storage/v1.17.0) (2021-09-28)