@RequiresApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
    public ChooserDialog withOnDismissListener(final DialogInterface.OnDismissListener listener) {
        _onDismissListener = listener;
        return this;
    }
onCancelListener will be triggered on back pressed or clicked outside of dialog
android-file-chooser/src/main/java/com/obsez/android/lib/filechooser/ChooserDialog.java