Removes unused constant

abstract class TutorialFragment extends Fragment implements OnTouchListener {

    private static final String LOG_TAG = "TutorialFragment";

    private static final String SYSTEM_NAVIGATION_SETTING_INTENT =

            "#Intent;action=com.android.settings.SEARCH_RESULT_TRAMPOLINE;S"

                    + ".:settings:fragment_args_key=gesture_system_navigation_input_summary;S"

                    + ".:settings:show_fragment=com.android.settings.gestures"

                    + ".SystemNavigationGestureSettings;end";

    static final String KEY_TUTORIAL_TYPE = "tutorial_type";

    TutorialType mTutorialType;