fix: TS definition (googleapis#387)

Fixes googleapis#385

Author: stephenplusplus

handwritten/storage/src/bucket.ts

@@ -76,7 +76,7 @@ interface MetadataRequest {
  */
 export interface GetFilesRequest {
   autoPaginate?: boolean;
-  delimited?: string;
+  delimiter?: string;
   directory?: string;
   prefix?: string;
   maxApiCalls?: number;