title: gradlew testDebugUnitTest mergeAndroidReports
body: <p>It's of my understanding that for running only the unit tests following is used:</p>
  
  <pre><code>gradlew testDebugUnitTest
  </code></pre>
  
  <p>This also works and report gets generated, but if I write following:</p>
  
  <pre><code>gradlew testDebugUnitTest mergeAndroidReports
  </code></pre>
  
  <p>I get:</p>
  
  <pre><code>Execution failed for task ':app:connectedDebugAndroidTest'.
  &gt; com.android.builder.testing.api.DeviceException: No connected devices!
  </code></pre>
  
  <p>So it's trying to also run the instrumentation tests, is this supposed to be expected or is this a bug?</p>
  
  <p>Seen on Android Studio 4 Canary 9 with latest gradle version (4.0.0-alpha09).</p>
  
  <p><a href="https://developer.android.com/studio/test/command-line#multi-module-reports" rel="nofollow noreferrer">mergeAndroidReports </a></p>