Update docs/troubleshooting/firebase-issues/client_access_to_firestore_expired.md

Co-authored-by: Pooja Bhaumik <[email protected]>

Author: mrdavidorok

docs/troubleshooting/firebase-issues/client_access_to_firestore_expired.md

@@ -11,7 +11,7 @@ You may receive an email from Firebase with the subject:
 
 This message typically appears when your Firestore database is in **Test Mode** and the access duration has expired.
 
-Reason for This Message
+You are seeing this error message because of the following:
 
     When setting up Firestore for the first time, Firebase offers two rule options: