title: google map not working on both emulator and device
body: <p>I am trying to run a simple google map but its not working its showing only map background.checked on both emulator and device. </p>
  
  <p>xml file:-</p>
  
  <pre><code>&lt;fragment xmlns:android="http://schemas.android.com/apk/res/android"
      android:id="@+id/map"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      class="com.google.android.gms.maps.SupportMapFragment"/&gt;
  </code></pre>
  
  <p>Java class</p>
  
  <pre><code>import android.os.Bundle; import
  com.google.android.gms.maps.GoogleMap; import
  com.google.android.gms.maps.SupportMapFragment; import
  com.google.android.gms.maps.model.BitmapDescriptorFactory; import
  com.google.android.gms.maps.model.LatLng; import
  com.google.android.gms.maps.model.Marker; import
  com.google.android.gms.maps.model.MarkerOptions;
  
  public class LocationGB extends android.support.v4.app.FragmentActivity {     
      static final LatLng HAMBURG = new LatLng(53.558, 9.927); 
      static final LatLng KIEL = new LatLng(53.551, 9.993);
      private GoogleMap map;
       @Override protected void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_location);
          map = ((SupportMapFragment) getSupportFragmentManager().findFragmentById(android.R.id.content)).getMap();
  
          if (map!=null){
              Marker hamburg = map.addMarker(new MarkerOptions().position(HAMBURG)
                  .title("Hamburg"));
              Marker kiel = map.addMarker(new MarkerOptions()
                  .position(KIEL)
                  .title("Kiel")
                  .snippet("Kiel is cool")
                  .icon(BitmapDescriptorFactory
                  .fromResource(R.drawable.ic_launcher))); 
          }
      } 
  }
  </code></pre>