LiveView file upload test

Thanks @cblavier that definitely gets the correct field input.
Now I’m getting an error:

** (exit) exited in: GenServer.call(#PID<0.802.0>, {:chunk, "profile_test.png", 100, #PID<0.800.0>, #Phoenix.LiveViewTest.Element<selector: "#account_form input[type=\"file\"][name=\"profile_pic\"]", text_filter: nil, ...>}, 5000)
 ** (EXIT) shutdown: :closed

But I assume that’s related to something else.