Just spent way too much time trying to figure out this simple problem so I will share my answer here to save the next guy time. When you run a container from visual studio (using the green play button which says "Container (Dockerfile)") it means that visual studio is running that container for you.

In order to change the arguments in that run command you can click on the drop down menu attached to that green arrow button, and then select {YOUR PROJECT NAME} Debug Properties. then a menu should pop up and under the Docker launch profile you will find Container run arguments. So any help online you find which requires you to change the run command can be applied by adding the arguments there. Hope this helps someone!