Animating a circle light affect

[Eni5EEE]

Hi! I was wondering what is the easiest way to create an animation where this circle is revealed by this stroke coming in from the top from both sides to create the full circle. Almost as if the stoke is being filled in, hopefully that makes sense. 

[Rick Gerard]

The easiest way to do that would be to create a shape layer with an Ellipse and stroke only above the circle, then add Trim Paths and animate Start and End from 50, 50 to 0, 100, add some blur to soften the edge, and set the Shape layer as an Alpha Track Matte. 

The screenshot shows everything I did to reveal the circle on your sample image.

I've uploaded a project file for you to take a look at.

[Mylenium]

It's even simpler than Rick's solution: Effects --> Transition --> Radial Wipe. Set the mode to bidirectional, adjust the cenrter position, add some feather to the edges. No need for any extra layers or shape items.

Mylenium