Turn off kernel picker mru for stable. (microsoft#172587)

Author: rebornix

src/vs/workbench/contrib/notebook/browser/notebook.contribution.ts

@@ -885,7 +885,7 @@ configurationRegistry.registerConfiguration({
 				nls.localize('notebook.kernelPickerType.mru', "Experiment: show recently used kernels."),
 			],
 			tags: ['notebookLayout'],
-			default: 'mru'
+			default: 'all'
 		},
 		[NotebookSetting.outputScrolling]: {
 			markdownDescription: nls.localize('notebook.outputScrolling', "Use a scrollable region for notebook output when longer than the limit"),