fix(File): correct default keepFileName to false

Author: leeyeh

src/file.js

@@ -496,7 +496,7 @@ module.exports = function(AV) {
         const data = {
           key,
           name,
-          keep_file_name: true,
+          keep_file_name: authOptions.keepFileName,
           ACL: this._acl,
           mime_type: type,
           metaData: this.attributes.metaData,

storage.d.ts

@@ -48,6 +48,7 @@ interface CaptchaOptions {
 }
 
 interface FileSaveOptions extends AuthOptions {
+  keepFileName?: boolean;
   onprogress?: (
     event: {
       loaded: number;

test/file.js

@@ -28,7 +28,7 @@ describe('File', function() {
       var file = new AV.File(fileName, { base64: base64 });
       file.metaData('format', 'txt file');
       file.setACL(new AV.ACL());
-      return file.save().then(function() {
+      return file.save({ keepFileName: true }).then(function() {
         expect(file.url()).to.match(new RegExp(fileName + '$'));
         expect(file.ownerId()).to.be.ok();
         expect(file.id).to.be.ok();