Fixed #4113 Added integration tests to cover cell language unit tests (#5788)

* Fixed #4113

* Resolve PR comments

extensions/integration-tests/src/notebook.util.ts

@@ -35,6 +35,22 @@ export const pySparkNotebookContent: azdata.nb.INotebookContents = {
 	nbformat_minor: 2
 };
 
+export const notebookContentForCellLanguageTest: azdata.nb.INotebookContents = {
+	cells: [{
+		cell_type: CellTypes.Code,
+		source: '1+1',
+		metadata: {},
+		execution_count: 1
+	}],
+	metadata: {
+		'kernelspec': {
+			'name': ''
+		},
+	},
+	nbformat: 4,
+	nbformat_minor: 2
+};
+
 export const pythonNotebookMultipleCellsContent: azdata.nb.INotebookContents = {
 	cells: [{
 		cell_type: CellTypes.Code,