Updates to api/mail.go

Ensures that item.Attachment information is stored within the backup.

src/internal/connector/exchange/api/mail.go

@@ -130,13 +130,18 @@ func (c Mail) GetItem(
 	var errs *multierror.Error
 
 	if *mail.GetHasAttachments() || HasAttachments(mail.GetBody()) {
+		options := &users.ItemMessagesItemAttachmentsRequestBuilderGetRequestConfiguration{
+			QueryParameters: &users.ItemMessagesItemAttachmentsRequestBuilderGetQueryParameters{
+				Expand: []string{"microsoft.graph.itemattachment/item"},
+			},
+		}
 		for count := 0; count < numberOfRetries; count++ {
 			attached, err := c.largeItem.
 				Client().
 				UsersById(user).
 				MessagesById(itemID).
 				Attachments().
-				Get(ctx, nil)
+				Get(ctx, options)
 			if err == nil {
 				mail.SetAttachments(attached.GetValue())
 				break