How to make Floating Action Button background Gradient?

Question

The code for FAB:

Answer 1

The accepted answer is working fine but after adding the below line, it stretches the icon added on FAB

56dp

I am sharing the screenshots:

Previous FAB button

After adding design_fab_image_size in dimen.xml and adding android:src="@drawable/gradient", the icon get stretched:

To deal with this I replaced my gradient.xml with the following code:

Output: