Keep notebook kernel bindings for non-untitled notebooks after they c…

…lose (#173352)

And also only persist the selected kernel in the editor view state for untitled notebook editors
Fix #171385

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

@@ -88,6 +88,7 @@ import { FloatingClickMenu } from 'vs/workbench/browser/codeeditor';
 import { IDimension } from 'vs/editor/common/core/dimension';
 import { CellFindMatchModel } from 'vs/workbench/contrib/notebook/browser/contrib/find/findModel';
 import { INotebookLoggingService } from 'vs/workbench/contrib/notebook/common/notebookLoggingService';
+import { Schemas } from 'vs/base/common/network';
 
 const $ = DOM.$;
 
@@ -1693,7 +1694,9 @@ export class NotebookEditorWidget extends Disposable implements INotebookEditorD
 			}
 		}
 		state.contributionsState = contributionsState;
-		state.selectedKernelId = this.activeKernel?.id;
+		if (this.textModel?.uri.scheme === Schemas.untitled) {
+			state.selectedKernelId = this.activeKernel?.id;
+		}
 
 		return state;
 	}

src/vs/workbench/contrib/notebook/browser/services/notebookKernelServiceImpl.ts

@@ -16,6 +16,7 @@ import { IMenu, IMenuService, MenuId } from 'vs/platform/actions/common/actions'
 import { IContextKeyService } from 'vs/platform/contextkey/common/contextkey';
 import { IAction } from 'vs/base/common/actions';
 import { MarshalledId } from 'vs/base/common/marshallingIds';
+import { Schemas } from 'vs/base/common/network';
 
 class KernelInfo {
 
@@ -134,7 +135,7 @@ export class NotebookKernelService extends Disposable implements INotebookKernel
 		this._register(_notebookService.onWillRemoveNotebookDocument(notebook => {
 			const id = NotebookTextModelLikeId.str(notebook);
 			const kernelId = this._notebookBindings.get(id);
-			if (kernelId) {
+			if (kernelId && notebook.uri.scheme === Schemas.untitled) {
 				this.selectKernelForNotebook(undefined, notebook);
 			}
 			this._kernelSourceActionsUpdates.get(id)?.dispose();