UI: run selector toggle all doesn't toggle _on_ on first click

When there are [more than 40 runs](https://github.com/tensorflow/tensorboard/blob/master/tensorboard/components/tf_dashboard_common/tf-multi-checkbox.ts#L56), the run selector does not enable runs by default. Unlike my expectation, when no runs are selected, if you click on `Toggle All Runs`, runs do not get enabled. Only after the second click on the button, it toggles all runs. 