Improve method comments for TransactionOptions.

Author: tom-andersen

firebase-firestore/src/main/java/com/google/firebase/firestore/FirebaseFirestore.java

@@ -407,8 +407,8 @@ public Query collectionGroup(@NonNull String collectionId) {
   /**
    * Executes the given {@code updateFunction} and then attempts to commit the changes applied
    * within the transaction. If any document read within the transaction has changed, the
-   * updateFunction will be retried. If it fails to commit after 5 attempts, the transaction will
-   * fail.
+   * updateFunction will be retried. If it fails to commit after 5 attempts (the default failure
+   * limit), the transaction will fail.
    *
    * <p>The maximum number of writes allowed in a single transaction is 500, but note that each
    * usage of {@link FieldValue#serverTimestamp()}, {@link FieldValue#arrayUnion(Object...)}, {@link
@@ -441,8 +441,9 @@ private <ResultT> Task<ResultT> runTransaction(
   /**
    * Executes the given {@code updateFunction} and then attempts to commit the changes applied
    * within the transaction. If any document read within the transaction has changed, the
-   * updateFunction will be retried. If it fails to commit after 5 attempts, the transaction will
-   * fail.
+   * updateFunction will be retried. If it fails to commit after 5 attempts (the default failure
+   * limit), the transaction will fail. To have a different number of retries, use the {@link
+   * FirebaseFirestore#runTransaction(TransactionOptions, Transaction.Function)} method instead.
    *
    * @param updateFunction The function to execute within the transaction context.
    * @return The task returned from the updateFunction.