7.7 release notes titles (#7550)

FirebasePerformance/CHANGELOG.md

@@ -1,4 +1,4 @@
-# Unreleased
+# Version 7.7.0
 * Add community supported tvOS.
 
 # Version 7.6.0

Firestore/CHANGELOG.md

@@ -1,4 +1,4 @@
-# Unreleased
+# v7.7.0
 - [fixed] Fixed a crash that could happen when the App is being deleted and
   there's an active listener (#6909).
 - [fixed] Fixed a bug where local cache inconsistencies were unnecessarily

Functions/CHANGELOG.md

@@ -1,4 +1,4 @@
-# Unreleased
+# v7.7.0
 - [fixed] Fixed missing "http://" prefix when using Functions with the emulator. (#7537, #7538)
 
 # v7.2.0