csharp.listRemoteProcess does not work in Alpine .NET images

[bwateratmsft]

Issue Description

The csharp.listRemoteProcess command would be helpful in Docker extension scenarios, because our debugging all happens through a pipe program (namely, docker exec). However, the implementation of it doesn't work in Alpine (or Debian, but that is a different bug) because the -x option does not work.

Steps to Reproduce

1. Scaffold a .NET (Core) app
2. With the C# extension, add the build and debug assets
3. With the Docker extension, do Add Dockerfiles.... Say "Yes" to Compose files.
4. Right click docker-compose.yaml and do Compose Up.
5. Go to the Debug tab. Add a debug configuration for "Docker .NET Core Attach (Preview)". Add "processId": "${command:csharp.listRemoteProcess}" to that config. (Ordinarily this isn't needed since only one dotnet process exists in the container, but in some scenarios--like dotnet watch--more than one exists)
6. F5 that config

Expected Behavior

Remote processes are listed to pick from

Actual Behavior

Error popup reading "See remote-attach output".

On an Alpine image:

Executing: docker exec -i netcore2020_netcore2020_1 sh -s < "c:\Users\bwater\.vscode\extensions\ms-dotnettools.csharp-1.23.1\scripts\remoteProcessPickerScript"
Linux
stderr: ps: unrecognized option: x
BusyBox v1.31.1 () multi-call binary.

Usage: ps [-o COL1,COL2=HEADER]

Show list of processes

	-o COL1,COL2=HEADER	Select columns for display
Error Message: Command failed: docker exec -i netcore2020_netcore2020_1 sh -s < "c:\Users\bwater\.vscode\extensions\ms-dotnettools.csharp-1.23.1\scripts\remoteProcessPickerScript"
ps: unrecognized option: x
BusyBox v1.31.1 () multi-call binary.

Usage: ps [-o COL1,COL2=HEADER]

Show list of processes

	-o COL1,COL2=HEADER	Select columns for display

*Note: VSDBG is present in the container so scripts are not the only option

Logs

OmniSharp log

Starting OmniSharp server at 8/28/2020, 10:13:42 AM Target: d:\Sandbox\NetCore2020 ``` OmniSharp server started. Path: c:\Users\bwater\.vscode\extensions\ms-dotnettools.csharp-1.23.1\.omnisharp\1.37.0\OmniSharp.exe PID: 16612

Starting OmniSharp on Windows 6.2.9200.0 (x64)
info: OmniSharp.Services.DotNetCliService
DotNetPath set to dotnet
info: OmniSharp.MSBuild.Discovery.MSBuildLocator
Located 2 MSBuild instance(s)
1: Visual Studio Enterprise 2019 16.6.30225.117 - "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\MSBuild\Current\Bin"
2: StandAlone 16.8.0 - "c:\Users\bwater.vscode\extensions\ms-dotnettools.csharp-1.23.1.omnisharp\1.37.0.msbuild\Current\Bin"
info: OmniSharp.MSBuild.Discovery.MSBuildLocator
Registered MSBuild instance: Visual Studio Enterprise 2019 16.6.30225.117 - "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\MSBuild\Current\Bin"
info: OmniSharp.Cake.CakeProjectSystem
Detecting Cake files in 'd:\Sandbox\NetCore2020'.
info: OmniSharp.Cake.CakeProjectSystem
Could not find any Cake files
info: OmniSharp.MSBuild.ProjectSystem
No solution files found in 'd:\Sandbox\NetCore2020'
info: OmniSharp.MSBuild.ProjectManager
Queue project update for 'd:\Sandbox\NetCore2020\NetCore2020.csproj'
info: OmniSharp.Script.ScriptProjectSystem
Detecting CSX files in 'd:\Sandbox\NetCore2020'.
info: OmniSharp.Script.ScriptProjectSystem
Could not find any CSX files
info: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.CSharpFormattingWorkspaceOptionsProvider, Order: 0
info: OmniSharp.MSBuild.ProjectManager
Loading project: d:\Sandbox\NetCore2020\NetCore2020.csproj
info: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.RenameWorkspaceOptionsProvider, Order: 100
info: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.ImplementTypeWorkspaceOptionsProvider, Order: 110
info: OmniSharp.WorkspaceInitializer
Invoking Workspace Options Provider: OmniSharp.Roslyn.CSharp.Services.BlockStructureWorkspaceOptionsProvider, Order: 140
info: OmniSharp.WorkspaceInitializer
Configuration finished.
info: OmniSharp.Stdio.Host
Omnisharp server running using Stdio at location 'd:\Sandbox\NetCore2020' on host 14316.
info: OmniSharp.MSBuild.ProjectManager
Successfully loaded project file 'd:\Sandbox\NetCore2020\NetCore2020.csproj'.
info: OmniSharp.MSBuild.ProjectManager
Adding project 'd:\Sandbox\NetCore2020\NetCore2020.csproj'
info: OmniSharp.MSBuild.ProjectManager
Update project: NetCore2020

```

C# log

(No C# logs)

Environment information

VSCode version: 1.48.2
C# Extension: 1.23.1

Dotnet Information

.NET SDK (reflecting any global.json): Version: 5.0.100-preview.4.20258.7 Commit: 65f0fc2cad

Runtime Environment:
OS Name: Windows
OS Version: 10.0.19041
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\5.0.100-preview.4.20258.7\

Host (useful for support):
Version: 5.0.0-preview.4.20251.6
Commit: 47ec733ba7

.NET SDKs installed:
3.1.301 [C:\Program Files\dotnet\sdk]
5.0.100-preview.4.20258.7 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.All 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.1.19 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.All 2.2.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.All]
Microsoft.AspNetCore.App 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.1.19 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 2.2.7 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 3.1.5 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.AspNetCore.App 5.0.0-preview.4.20257.10 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 2.1.12 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.13 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.1.19 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 2.2.7 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 3.1.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.NETCore.App 5.0.0-preview.4.20251.6 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 3.1.5 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]
Microsoft.WindowsDesktop.App 5.0.0-preview.4.20251.1 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

To install additional .NET runtimes or SDKs:
https://aka.ms/dotnet-download

Visual Studio Code Extensions

Extension	Author	Version
azure-account	ms-vscode	0.9.2
csharp	ms-dotnettools	1.23.1
hexeditor	ms-vscode	1.2.1
js-debug-nightly	ms-vscode	2020.8.2017
nls-string-extractor	bwateratmsft	0.0.5
prettify-json	mohsen1	0.0.3
python	ms-python	2020.8.105045
remote-containers	ms-vscode-remote	0.134.1
remote-ssh	ms-vscode-remote	0.51.0
remote-ssh-edit	ms-vscode-remote	0.51.0
remote-wsl	ms-vscode-remote	0.44.4
vscode-docker	ms-azuretools	1.6.0-alpha
vscode-eslint	dbaeumer	2.1.8
vscode-remote-extensionpack	ms-vscode-remote	0.20.0
vscodeintellicode	VisualStudioExptTeam	1.2.10
vsonline	ms-vsonline	1.0.2688

[gregg-miskelly]

@bwateratmsft we decided to split this bug into two -- this issue will track changing our usage of ps to work on Alpine. See #4096 for Debian.