Add safety net if StackView duration would be negative.

                float d = (float) Math.hypot(viewLp.horizontalOffset, viewLp.verticalOffset);

                float maxd = (float) Math.hypot(mSlideAmount, 0.4f * mSlideAmount);

                if (d > maxd) {

                    // Because mSlideAmount is updated in onLayout(), it is possible that d > maxd

                    // if we get onLayout() right before this method is called.

                    d = maxd;

                }

                if (velocity == 0) {

                    return (invert ? (1 - d / maxd) : d / maxd) * DEFAULT_ANIMATION_DURATION;