There is no automated way to add animated profile picture on Gmail. You’d first need to create the GIF by using online tools like remove.bg and Canva, and then upload that GIF as your profile picture ...
To make a GIF on your iPhone, you can convert a Live Photo using the Photos app, or get an app like GIPHY.
You can make a GIF on your Samsung Galaxy S10 in just a few steps. Here's what you need to know to do it.