I am wondering how app developers create games with 3D animations and graphics. Does anyone know how those games are made, and can it be done with android studio?
Yes, it can be done with Android Studio.
If you wanted to hand-code it, you would just create a GLSurfaceView, and draw objects into it. Here's a basic tutorial: Displaying Graphics with OpenGL ES
But, you would never hand-code it in real life. To make even a simple 3D game, you would want to use a game engine like Unity3D or jPCT-AE.
Any decent 3D engine will have tools for porting to Android. And many of them have communities that can offer support and troubleshooting.