Prepare release for storage (Azure#28739)

* update changelog

* prepare release

* update changelog to include more changes

Author: ArcturusZhang

sdk/storage/Azure.ResourceManager.Storage/CHANGELOG.md

@@ -1,14 +1,13 @@
 # Release History
 
-## 1.0.0-beta.9 (Unreleased)
-
-### Features Added
+## 1.0.0-beta.9 (2022-05-13)
 
 ### Breaking Changes
 
-### Bugs Fixed
-
-### Other Changes
+- Flattened property from a read-only model no longer has setters.
+- The type of flattened primitive property changed to its corresponding nullable type.
+- Renamed class `PrivateLinkResource` to `StoragePrivateLinkResource`.
+- Added an `Update` method using the implementation of `CreateOrUpdate` if the resource previously does not have a `Update` method.
 
 ## 1.0.0-beta.8 (2022-04-08)