nuxeo-checkmark is not clickable on nuxeo-data-table

After the release of the new Polymer version (ELEMENTS-1174), nuxeo-checkmark is not properly working on nuxeo-data-table.

After a brief analysis we found out a few things:

• changing the on-click to on-tap on nuxeo-checkmark allows us to click on it and checking it; however, if you click on it again we are unable to uncheck it;
• observing data-table-checkbox.js we see that the binding between it and nuxeo-checkmark is not working;
• the problem probably relies on their parents, data-table-row.js, and the way it's observer is reacting to the selected property.