How to add shadow in android vector drawable?

Question

Android

How to add a shadow to a drawable vector file in Android? The shadow must be added to a specific path element.
The element can be non-standard (not round, and not square) shape.
The shadow should be exactly a shadow, that is, gradually fade around the edges, and not the bottom layer of black with a transparency of 20%.
An example of what the image should look like after adding it to activity.xml: