Update Javadoc for EXTRA_NETWORK.

     * The lookup key for a {@link Network} object included with the intent after

     * successfully finding a network for the applications request.  Retrieve it with

     * {@link android.content.Intent#getParcelableExtra(String)}.

     * <p>

     * Note that if you intend to invoke (@link #setProcessDefaultNetwork(Network)) or

     * {@link Network#openConnection(java.net.URL)} then you must get a

     * ConnectivityManager instance before doing so.

     */

    public static final String EXTRA_NETWORK = "android.net.extra.NETWORK";