title: Android: how to lose focus on editText when testing with espresso
body: <p>I want to test my error message in my android app. My error check only happens when the focus of my editText changes. </p>
  
  <pre><code>@Test
      fun wrongFirstname(){
          onView(withId(R.id.txtFirstNameRegister)).perform(typeText(""))
          //here I need to lose my focus
          onView(withId(R.id.txtFirstNameRegister)).check(matches(hasErrorText(R.string.firstNameCheckError.toString())))
      }
  </code></pre>