Rally App SDK 2.0: how to get tooltip on
===

If I have a rallygrid of PortfolioItems and I include PercentDoneByStoryPlanEstimate in the column configs, I get the progress bar as expected.  But when I hover over the progress bar, I don't see the tooltip with extra information that I see in Rally itself.

How do I get the tooltip to display in an app?

Sample code:

        Rally.onReady(function() {
            Ext.define('CustomApp', {
                extend: 'Rally.app.App',
                componentCls: 'app',
            
                launch: function() {
                    Rally.data.ModelFactory.getModel({
                        type: 'PortfolioItem',
                        success: function(model) {
                            this.grid = this.add({
                                xtype: 'rallygrid',
                                model: model,
                                columnCfgs: [
                                    'FormattedID',
                                    'Name',
                                    'PercentDoneByStoryPlanEstimate'
                                ]
                            });
                        },
                        scope: this
                    });
                }
            });

            Rally.launchApp('CustomApp', {
                name: 'Grid Example'
            });
        });