Update changelog with 3.27 changes (flutter#160105)

Author: christopherfujino

CHANGELOG.md

@@ -24,6 +24,12 @@ docs/releases/Hotfix-Documentation-Best-Practices.md
 
 INTERNAL NOTE
 -->
+
+## Flutter 3.27 Changes
+
+### [3.27.0](https://github.com/flutter/flutter/releases/tag/3.27.0)
+Initial stable release.
+
 ## Flutter 3.24 Changes
 ### [3.24.4](https://github.com/flutter/flutter/releases/tag/3.24.4)
 - [dart 3.5.4 changelog](https://github.com/dart-lang/sdk/blob/stable/CHANGELOG.md#354---2024-10-17)