This signals the chrome missing dependency that should get installed with that:

RUN apt-get update && \ apt-get install -y gnupg libgconf-2-4 wget && \ wget -q -O - https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add - && \ sh -c 'echo "deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main" >> /etc/apt/sources.list.d/google.list' && \ apt-get update && \ apt-get install -y google-chrome-unstable --no-install-recommends ENV chrome:launchOptions:args --no-sandbox

It seems you have twice FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base in your dockerfile.
It should be there just once. Maybe the apt-get part isn't running actually. Please remove the second FROM declaration and try it again.