UID in client is only adapted if switched to non-root via name but not if switched via UID in dockerfile.

[user1584]

• VSCode Version: 1.74.3
• Local OS Version: Ubuntu 20.04
• Local chip architecture: x86
• Reproduces in: Remote - Containers
• Name of Dev Container Definition with Issue:

Steps to Reproduce:

1. In the client, create a non-root user and switch to non-root user via UID instead of the user name

FROM ubuntu AS test

ARG NON_ROOT_USER=non_root_user
ARG NON_ROOT_UID=1000
ARG NON_ROOT_GID=100

USER root

# Create non-root user
RUN useradd \
    --no-log-init \
    --no-user-group \
    --shell /bin/bash \
    --create-home \
    --uid ${NON_ROOT_UID} \
    --gid ${NON_ROOT_GID} \
    ${NON_ROOT_USER}

# This works:
# USER ${NON_ROOT_USER} 

 # This does not work:
USER ${NON_ROOT_UID}

2. Start devcontainer with

{
  "build": {
    "dockerfile": "Dockerfile",
    "target": "test"
  },
  "runArgs": [
    "--rm"
  ]
}

3. Check the UID of the User within the devcontainer via id. If switching to the non-root user via USER ${NON_ROOT_USER}, you should get the UID of the user from the host. If switching via USER ${NON_ROOT_UID}, the UID will remain at 1000.