Update Changelog.md (#20233)

* Update Changelog.md

* Update src/BotService/Changelog.md

Co-authored-by: Beisi Zhou <[email protected]>

Author: Nickcandy

src/BotService/Changelog.md

@@ -18,6 +18,7 @@
         - Additional information about change #1
 -->
 ## Upcoming Release
+* Upgraded API version to 2022-06-15-preview.
 
 ## Version 0.4.0
 * Fixed issue of `-Location` in `New-AzBotService`[#17185]