[phone numbers sdk] Release 1.2.0-beta3 (Azure#21253)

Author: automagicaly

sdk/communication/communication-phone-numbers/CHANGELOG.md

@@ -1,15 +1,11 @@
 # Release History
 
-## 1.2.0-beta.3 (Unreleased)
+## 1.2.0-beta.3 (2022-04-06)
 
 ### Features Added
 
 - Added environment variable `AZURE_USERAGENT_OVERRIDE` that overrides the HTTP header `x-ms-useragent` during tests
 
-### Breaking Changes
-
-### Bugs Fixed
-
 ### Other Changes
 
 - Update minimum version of dependency "@azure/core-client" to "1.5.0", which allows adding additional policies to the rest pipeline after initialization.