Clone Repository in Container Volume does not respect proxy settings

• VSCode Version: 1.55.1
• Local OS Version: Win 10 20H2
• Remote OS Version: n/a
• Remote Extension/Connection Type: Docker

Information:

When trying to clone a repository in a container volume the volume bootstrap image is trying to run apk add commands. My network environment requires the use of a proxy server so this will not work without the proxy settings configured but there is no way to provide theses settings.

Steps to Reproduce:

1. Must be in an environment that requires the use of a proxy server for all outbound internet traffic.
2. Run "Remote-Containers: Clone Repository in Container Volume..." with any URL (e.g. https://github.com/microsoft/vscode-remote-try-go)
3. Select either "Create a unique volume" or "Create a new volume"

Output:

[7 ms] Remote-Containers 0.166.1 in VS Code 1.55.1 (08a217c4d27a02a5bcde898fd7981bda5b49391b).
[345 ms] Start: Resolving Remote
[348 ms] Start: Check Docker is running
[348 ms] Start: Run: docker version --format {{.Server.APIVersion}}
[711 ms] Server API version: 1.41
[713 ms] Start: Run: docker volume ls -q
[1097 ms] Start: Run: docker volume create --label vsch.local.repository=https://github.com/microsoft/vscode-remote-try-go --label vsch.local.repository.unique=true vscode-remote-try-go-c988b944cb6f625015fbf2724d594c80
[1517 ms] Start: Run: docker ps -q -a --filter label=vsch.local.repository=https://github.com/microsoft/vscode-remote-try-go --filter label=vsch.local.repository.volume=vscode-remote-try-go-c988b944cb6f625015fbf2724d594c80 --filter label=vsch.local.repository.folder=vscode-remote-try-go --filter label=vsch.quality=stable
[1950 ms] Start: Run: docker build -f c:\Users\User\.vscode\extensions\ms-vscode-remote.remote-containers-0.166.1\scripts\volumeBootstrap.Dockerfile -t vsc-volume-bootstrap c:\Users\User\.vscode\extensions\ms-vscode-remote.remote-containers-0.166.1\scripts

[+] Building 44.6s (5/5) FINISHED
 => [internal] load build definition from volumeBootstrap.Dockerfile                                                                                                                                 0.0s
 => => transferring dockerfile: 47B                                                                                                                                                                  0.0s
 => [internal] load .dockerignore                                                                                                                                                                    0.0s
 => => transferring context: 2B                                                                                                                                                                      0.0s
 => [internal] load metadata for docker.io/library/alpine:3.13.2                                                                                                                                     1.8s
 => CACHED [1/2] FROM docker.io/library/alpine:3.13.2@sha256:a75afd8b57e7f34e4dad8d65e2c7ba2e1975c795ce1ee22fa34f8cf46f96a3be                                                                        0.0s
 => ERROR [2/2] RUN apk add --no-cache  nodejs  git  openssh-client  docker-cli  docker-compose  ;                                                                                                  42.6s
------
 > [2/2] RUN apk add --no-cache         nodejs  git     openssh-client  docker-cli                                                                                                                       d
ocker-compose   ;:
#5 0.387 fetch https://dl-cdn.alpinelinux.org/alpine/v3.13/main/x86_64/APKINDEX.tar.gz
#5 21.53 fetch https://dl-cdn.alpinelinux.org/alpine/v3.13/community/x86_64/APKINDEX.tar.gz
#5 21.53 WARNING: Ignoring https://dl-cdn.alpinelinux.org/alpine/v3.13/main: network error (check Internet connection and firewall)
#5 42.60 WARNING: Ignoring https://dl-cdn.alpinelinux.org/alpine/v3.13/community: network error (check Internet connection and firewall)
#5 42.60 ERROR: unable to select packages:
#5 42.60   docker-cli (no such package):
#5 42.60     required by: world[docker-cli]
#5 42.60   docker-compose (no such package):
#5 42.60     required by: world[docker-compose]
#5 42.60   git (no such package):
#5 42.60     required by: world[git]
#5 42.60   nodejs (no such package):
#5 42.60     required by: world[nodejs]
#5 42.60   openssh-client (no such package):
#5 42.60     required by: world[openssh-client]
------
executor failed running [/bin/sh -c apk add --no-cache  nodejs  git     openssh-client                                                                                                                   d
ocker-cli       docker-compose  ;]: exit code: 5
[47331 ms] Command failed: docker build -f c:\Users\User\.vscode\extensions\ms-vscode-remote.remote-containers-0.166.1\scripts\volumeBootstrap.Dockerfile -t vsc-volume-bootstrap c:\Users\User\.vscode\extensions\ms-vscode-remote.remote-containers-0.166.1\scripts

Workaround:
If I edit the volumeBoostrap.Dockerfile and add proxy env vars then it works but this is hardly ideal as it would have to be done after every update of the extension.