[Dashboard] Start using /list_tests's test_path_dict mode in test-picker

dashboard/dashboard/static/series_group_test.html

Index: dashboard/dashboard/static/series_group_test.html
diff --git a/dashboard/dashboard/static/series_group_test.html b/dashboard/dashboard/static/series_group_test.html
index eb28d5b39625927ac8417017d2e0315bce0fa293..c93aeb38520db1b2e1005d6bbc8e64024cfd4f47 100644
--- a/dashboard/dashboard/static/series_group_test.html
+++ b/dashboard/dashboard/static/series_group_test.html
@@ -25,13 +25,13 @@ tr.b.unittest.testSuite(() => {
   test('requestParamsSelected', () => {
     const element = ['foo', []];
     const params = d.listTestsRequestParams(element, true);
-    assert.strictEqual(params.selected, '1');
+    assert.strictEqual(params.return_selected, '1');
   });
 
   test('requestParamsUnselected', () => {
     const element = ['foo', []];
     const params = d.listTestsRequestParams(element, false);
-    assert.strictEqual(params.selected, '0');
+    assert.strictEqual(params.return_selected, '0');
   });
 
   test('requestParamsAll', () => {