SNOW-1889398: Handle endpoint without protocol for GCS (#994)

Author: sfc-gh-dprzybysz

lib/file_transfer_agent/gcs_util.js

@@ -462,7 +462,7 @@ function GCSUtil(connectionConfig, httpClient, fileStream) {
     const fullFilePath = `${gcsLocation.path}${filename}`;
     const endPoint = this.getGCSCustomEndPoint(stageInfo);
     const link = `${endPoint != null ? endPoint : 'https://storage.googleapis.com'}/${gcsLocation.bucketName}/${fullFilePath}`;
-    return link;
+    return link.startsWith('https://') ? link : `https://${link}`;
   };
 
   this.getGCSCustomEndPoint = function (stageInfo) {