Fix javadoc attr reference.

     * have its entry in recent tasks removed when the user closes it (with back

     * or however else it may finish()). If you would like to instead allow the

     * document to be kept in recents so that it can be re-launched, you can use

     * this flag.  When set and the task's activity is finished, the recents entry

     * will remain in the interface for the user to re-launch it, like a recents

     * entry for a top-level application.

     *

     * <p>The receiving activity can override this request with

     * {@link android.R.styleable#AndroidManifestActivity_autoRemoveFromRecents}

     * or by explcitly calling {@link android.app.Activity#finishAndRemoveTask()

     * this flag. When set and the task's activity is finished, the recents

     * entry will remain in the interface for the user to re-launch it, like a

     * recents entry for a top-level application.

     * <p>

     * The receiving activity can override this request with

     * {@link android.R.attr#autoRemoveFromRecents} or by explcitly calling

     * {@link android.app.Activity#finishAndRemoveTask()

     * Activity.finishAndRemoveTask()}.

     */

    public static final int FLAG_ACTIVITY_RETAIN_IN_RECENTS = 0x00002000;