Replace `DocumentListenOptions` with a simple boolean. (#1099)

* Replace `DocumentListenOptions` with a simple boolean.

Instead of calling

  `addSnapshotListener(options: DocumentListenOptions.includeMetadataChanges(true))`

call

  `addSnapshotListener(includeMetadataChanges:true)`

* Style

1 files changed, 13 insertions, 1 deletions

diff --git a/Firestore/Example/SwiftBuildTest/main.swift b/Firestore/Example/SwiftBuildTest/main.swift
index 691adf6..555a75b 100644
--- a/Firestore/Example/SwiftBuildTest/main.swift
+++ b/Firestore/Example/SwiftBuildTest/main.swift
@@ -255,6 +255,19 @@ func listenToDocument(at docRef: DocumentReference) {
   listener.remove()
 }
 
+func listenToDocumentWithMetadataChanges(at docRef: DocumentReference) {
+  let listener = docRef.addSnapshotListener(includeMetadataChanges: true) { document, error in
+    if let document = document {
+      if document.metadata.hasPendingWrites {
+        print("Has pending writes")
+      }
+    }
+  }
+
+  // Unsubscribe.
+  listener.remove()
+}
+
 func listenToDocuments(matching query: Query) {
   let listener = query.addSnapshotListener { snap, error in
     if let error = error {
@@ -330,7 +343,6 @@ func transactions() {
 func types() {
   let _: CollectionReference
   let _: DocumentChange
-  let _: DocumentListenOptions
   let _: DocumentReference
   let _: DocumentSnapshot
   let _: FieldPath