Bug 1067234 - [ICE Contacts] Create an integration test for bug 1062595 ...

...(confirm window when deleting phone numbers)
Everything points to the gaia-header element creating an .action-button that implements the arrow to go back, but I haven't been able to select any element with that class from the test or the App Manager debugger, and selecting that element directly from the debugger marks no element in the HTML. I don't know yet why does this happen but it has to be the reason why this more difficult process to click the arrow had to be used in previous tests.