Mark package as In Release (Azure#37990)

Author: sofiar-msft

sdk/communication/Azure.Communication.PhoneNumbers/CHANGELOG.md

@@ -1,16 +1,10 @@
 # Release History
 
-## 1.2.0-beta.1 (Unreleased)
+## 1.2.0-beta.1 (2023-08-08)
 
 ### Features Added
 - Added custom page sizes to PurchasedPhoneNumbers, Countries, Localities, AreaCodes and Offerings. 
 
-### Breaking Changes
-
-### Bugs Fixed
-
-### Other Changes
-
 ## 1.1.0 (2023-03-28)
 
 ### Features Added