Change lines:
mFloatingActionButton.hide(); -> LayoutXyScaleAnim.hide(mFloatingActionButton, this);
mFloatingActionButton.show(); -> LayoutXyScaleAnim.show(mFloatingActionButton, this);

And the code for hide/show is actually:

public static void show(final View target, Context context) {
        target.setVisibility(View.VISIBLE);
        AnimatorSet layoutShownAnim = (AnimatorSet) AnimatorInflater.loadAnimator(context, R.animator.layout_xy_scale_show);
        layoutShownAnim.setTarget(target);
        layoutShownAnim.addListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animation) { }
            @Override
            public void onAnimationEnd(Animator animation) { target.setVisibility(View.VISIBLE); }
            @Override
            public void onAnimationCancel(Animator animation) { }
            @Override
            public void onAnimationRepeat(Animator animation) {}
        });
        layoutShownAnim.start();
    }

    public static void hide(final View target, Context context) {
        AnimatorSet layoutHiddenAnim = (AnimatorSet) AnimatorInflater.loadAnimator(context, R.animator.layout_xy_scale_hide);
        layoutHiddenAnim.setTarget(target);
        layoutHiddenAnim.addListener(new Animator.AnimatorListener() {
            @Override
            public void onAnimationStart(Animator animation) { }
            @Override
            public void onAnimationEnd(Animator animation) { target.setVisibility(View.GONE); }
            @Override
            public void onAnimationCancel(Animator animation) { }
            @Override
            public void onAnimationRepeat(Animator animation) {}
        });
        layoutHiddenAnim.start();
    }

layout_xy_scale_show:

<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:ordering="together">

    <objectAnimator
        android:duration="200"
        android:propertyName="scaleX"
        android:valueType="floatType"
        android:valueFrom="0.0f"
        android:valueTo="1.0f" />

    <objectAnimator
        android:duration="200"
        android:propertyName="scaleY"
        android:valueType="floatType"
        android:valueFrom="0.0f"
        android:valueTo="1.0f" />
</set>

layout_xy_scale_hide

<set xmlns:android="http://schemas.android.com/apk/res/android"
    android:ordering="together">
    <objectAnimator
        android:duration="200"
        android:propertyName="scaleX"
        android:valueType="floatType"
        android:valueFrom="1.0f"
        android:valueTo="0.0f" />

    <objectAnimator
        android:duration="200"
        android:propertyName="scaleY"
        android:valueType="floatType"
        android:valueFrom="1.0f"
        android:valueTo="0.0f" />
</set>