smoke - simplify line number test (microsoft#141054)

Author: bpasero

smoke/src/areas/preferences/preferences.test.ts

@@ -3,7 +3,6 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import { join } from 'path';
 import { Application, ActivityBarPosition, Logger } from '../../../../automation';
 import { installAllHandlers } from '../../utils';
 
@@ -15,16 +14,17 @@ export function setup(logger: Logger) {
 
 		it('turns off editor line numbers and verifies the live change', async function () {
 			const app = this.app as Application;
-			await app.workbench.quickaccess.openFile(join(app.workspacePathOrFolder, 'app.js'));
+
+			await app.workbench.settingsEditor.openUserSettingsFile();
 			await app.code.waitForElements('.line-numbers', false, elements => !!elements.length);
 
 			await app.workbench.settingsEditor.addUserSetting('editor.lineNumbers', '"off"');
-			await app.workbench.settingsEditor.openUserSettingsFile();
 			await app.code.waitForElements('.line-numbers', false, result => !result || result.length === 0);
 		});
 
 		it('changes "workbench.action.toggleSidebarPosition" command key binding and verifies it', async function () {
 			const app = this.app as Application;
+
 			await app.workbench.activitybar.waitForActivityBar(ActivityBarPosition.LEFT);
 
 			await app.workbench.keybindingsEditor.updateKeybinding('workbench.action.toggleSidebarPosition', 'View: Toggle Side Bar Position', 'ctrl+u', 'Control+U');