title: PowerMock - static methods called from delayed RxJava stream
body: <p>I'm attempting to mock <code>BluetoothAdapter.getDefaultInstance()</code>, which works great per usual implementations, but is failing when the mock is accessed via a time-delayed RxJava stream.</p>
  
  <p>It's as if my call to...</p>
  
  <p><code>when(BluetoothAdapter.getDefaultAdapter()).thenReturn(null)</code></p>
  
  <p>...is never made and we receive a typical exception:</p>
  
  <p><code>java.lang.RuntimeException: Method getDefaultAdapter in android.bluetooth.BluetoothAdapter not mocked</code></p>
  
  <p>The context is in a stream similar to:</p>
  
  <pre><code>Observable
    .delay(1000, TimeUnit.MILLISECONDS)
    .doFinally(() -&gt; BluetoothAdapter.getDefaultInstance().getBluetoothLeScanner().stopScan())
    .subscribe();
  </code></pre>