A simple way to use ArrayLists within Parcelable while keeping the array null if not present.

MyUtils

public class MyUtils {
    private static final int PARCEL_LIST_NULL = 1151;
    private static final int PARCEL_LIST_NOTNULL = 1152;

    public static <T extends Parcelable> void appendListToParcel(Parcel out, @Nullable ArrayList<T> list) {
        if (list == null) {
            out.writeInt(PARCEL_LIST_NULL);
        } else {
            out.writeInt(PARCEL_LIST_NOTNULL);
            out.writeList(list);
        }
    }

    public static <T extends Parcelable> ArrayList<T> detachListFromParcel(Parcel in, ClassLoader cl) {
        boolean isNull = in.readInt() == PARCEL_LIST_NULL;
        if (!isNull) {
            ArrayList<T> test = new ArrayList<>();
            in.readList(test, cl);
            return test;
        }
        return null;
    }
}

Your parcelable class

public class MyClass implements Parcelable {
    // "OtherClass" implements parcelable as well. 
    private ArrayList<OtherClass> list;
    
    private MyClass(Parcel in) {
        ArrayList<OtherClass> list = MyUtils.detachListFromParcel(in, OtherClass.class.getClassLoader());
        if (test != null) {
            topBadges = new ArrayList<>(test);
        }
    }
    @Override
    public void writeToParcel(Parcel dest, int flags) {
        MyUtils.appendListToParcel(dest, list);
    }
    
}