[ServiceBus] Changelog update (Azure#20189)

Author: yunhaoling

sdk/servicebus/azure-servicebus/CHANGELOG.md

@@ -1,17 +1,12 @@
 # Release History
 
-## 7.3.2 (Unreleased)
-
-### Features Added
-
-### Breaking Changes
+## 7.3.2 (2021-08-10)
 
 ### Bugs Fixed
+
 - Fixed a bug that `azure.servicebus.aio.AutoLockRenewer` crashes on disposal if no messages have been registered (#19642).
 - Fixed a bug that `azure.servicebus.AutoLockRenewer` only supports auto lock renewal for `max_workers` amount of messages/sessions at a time (#19362).
 
-### Other Changes
-
 ## 7.3.1 (2021-07-07)
 
 ### Fixed