title: Toast not showing in Android Q
body: <p><code>Toast</code> does not work in <strong>Android Q</strong>. Is there any change on <code>Toast</code>? I couldn't find any release note for <code>Toast</code>.<br>
  My code is simple.</p>
  
  <pre><code>override fun onCreate(savedInstanceState: Bundle?) {
      super.onCreate(savedInstanceState)
      setContentView(R.layout.activity_main)
  
      Toast.makeText(this, "onCreate", Toast.LENGTH_SHORT).show()
  }
  
  fun onButtonClick(view: View) {
      Toast.makeText(this, "onButtonClick", Toast.LENGTH_SHORT).show()
  }
  </code></pre>
  
  <p>This works fine with Android Pie, but no luck with Android Q.<br>
  What happened to <code>Toast</code>??</p>