[Release] Update CHANGELOGs for 10.9.0 release (#11146)

* [Release] Update CHANGELOGs for 10.9.0 release

* Review

Crashlytics/CHANGELOG.md

@@ -1,5 +1,7 @@
-# Unreleased
-- [fixed] Updated upload-symbols to 3.15. Disabled dSYM uploads for Flutter apps building with --obfuscate and added instructions for uploading through the Crashlytics dashboard. (#11136)
+# 10.9.0
+- [fixed] Updated upload-symbols to 3.15. Disabled dSYM uploads for Flutter
+  apps building with --obfuscate and added instructions for uploading through
+  the Crashlytics dashboard. (#11136)
 - [fixed] Fixed a memory leak when generating session events (#11027).
 
 # 10.7.0

FirebaseAppCheck/CHANGELOG.md

@@ -1,4 +1,4 @@
-# Unreleased
+# 10.9.0
 - [feature] Added `limitedUseToken(completion:)` for obtaining limited-use tokens for
   protecting non-Firebase backends. (#11086)
 

FirebasePerformance/CHANGELOG.md

@@ -1,4 +1,4 @@
-# Unreleased
+# 10.9.0
 - [fixed] Fixed a memory leak when generating session events (#11027).
 
 # 10.6.0

Firestore/CHANGELOG.md

@@ -1,4 +1,4 @@
-# Unreleased
+# 10.9.0
 - [feature] Add new cache config API to customize SDK cache settings.
 - [feature] Add LRU garbage collector as an option to memory cache.