title: UiDevice class missing from UIAutomator 2.1.2
body: <p>I found that "upgrading" my reference to UIAutomator in build.gradle to 2.1.2 broke any references I had to the UiDevice class. In fact, a lot seems to have changed but I'm finding nothing explaining it. </p>
  
  <p>Can anyone shed some light on what is (apparently) about to change?</p>
  
  <p>This works: </p>
  
  <pre><code>androidTestCompile 'com.android.support.test.uiautomator:uiautomator-v18:2.1.1'
  </code></pre>
  
  <p>This does not:</p>
  
  <pre><code>androidTestCompile 'com.android.support.test.uiautomator:uiautomator-v18:2.1.2'
  </code></pre>
  
  <p>Dependencies from build.gradle follow (made a mess of by trying to figure this out):</p>
  
  <pre><code>testCompile 'junit:junit:4.12'
  // Optional -- Mockito framework
  testCompile 'org.mockito:mockito-core:1.10.19'
  
  androidTestCompile('com.android.support.test.espresso:espresso-core:3.0.0', {
      exclude group: 'com.android.support', module: 'support-annotations'
  })
  
  // Optional -- UI testing with UI Automator
  androidTestCompile 'com.android.support.test.uiautomator:uiautomator-v18:2.1.1'
  androidTestCompile 'com.android.support:support-annotations:26.0.0'
  androidTestCompile 'com.android.support.test:runner:1.0.0'
  androidTestCompile 'com.android.support.test:rules:1.0.0'
  // Optional -- Hamcrest library
  androidTestCompile 'org.hamcrest:hamcrest-library:1.3'
  
  // Optional -- UI testing with Espresso
  compile fileTree(include: ['*.jar'], dir: 'libs')
  compile 'com.android.volley:volley:1.0.0'
  compile 'com.google.code.gson:gson:2.8.0'
  compile 'com.android.support:appcompat-v7:26.0.0'
  compile 'com.android.support:design:26.0.0'
  compile 'com.android.support:support-v4:26.0.0'
  </code></pre>