How to make Button overlap CardView at the bottom

Question

I am creating an app that displays announcements, and I want to add a login. I am trying to make this XML design,

Answer 1

I have read every answer here and I have discarded every single becouse the following motives

1. I don't want to use negative margins, this is not recommended.
2. I don't want to user LinearLayout
3. The others answers dosen't work for me

So, finally I have solved my problem just wrapping the Button in another ConstraintLayout and adding some elevation to this ConstraintLayout

Here is my result

Here is a working sample