[Key Vault] Prepare patch release for keys (Azure#24059)

Author: mccoyp

sdk/keyvault/azure-keyvault-keys/CHANGELOG.md

@@ -1,14 +1,10 @@
 # Release History
 
-## 4.5.1 (Unreleased)
-
-### Features Added
-
-### Breaking Changes
+## 4.5.1 (2022-04-19)
 
 ### Bugs Fixed
-
-### Other Changes
+- Fixed error that could occur when fetching a key rotation policy that has no defined
+  `lifetime_actions`.
 
 ## 4.5.0 (2022-03-28)
 

sdk/keyvault/azure-keyvault-keys/azure/keyvault/keys/_models.py

@@ -341,7 +341,11 @@ def __init__(self, **kwargs):
 
     @classmethod
     def _from_generated(cls, policy):
-        lifetime_actions = [KeyRotationLifetimeAction._from_generated(action) for action in policy.lifetime_actions]  # pylint:disable=protected-access
+        lifetime_actions = (
+            None
+            if policy.lifetime_actions is None
+            else [KeyRotationLifetimeAction._from_generated(action) for action in policy.lifetime_actions]  # pylint:disable=protected-access
+        )
         if policy.attributes:
             return cls(
                 policy_id=policy.id,