title: Android 4.2 getSupportFragmentManager().getMap() returns null
body: <p>I've met this problem on Android 4.2.
  I have three devices, one has 4.1.1 on it, a two another have 4.2. On 4.1 phone getSupportFragmentManager().getMap() returns a map, I can see it, I can find my location and so on. But on two another it returns null.</p>
  
  <p>Here's my code on map setup:</p>
  
  <pre><code>mMap = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(R.id.map)).getMap();
  mMap.setMyLocationEnabled(true);
  mMap.getUiSettings().setMyLocationButtonEnabled(false);
  mMap.setOnMyLocationChangeListener(this);
  </code></pre>
  
  <p>On 4.2 each of last three lines throws NullPointerException. On 4.1 all of them work.</p>
  
  <p>I can't find, why it happens.</p>
  
  <p>PS: Google maps works great on 4.2. And "My location" button works too.
  PS2: In the settings "Access my location", "GPS Sattelites" and "Wi-Fi &amp; mobile network location" are turned on.</p>