Revert "Avoid hitting the UI thread when retrieving MEF specific services"

[kartheekp-ms]

…ices (#4229)

This reverts commits 38f679c that is not required for Preview 4.

Bug

Fixes: https://github.com/NuGet/Client.Engineering/issues/1122

Regression? Last working version:

Description

VS insertion PR for preview 4 is failing because of null reference exception thrown by below method. VS Pull request link is specified in the linked issue.

NuGet.Client/src/NuGet.Clients/NuGetConsole.Host.PowerShell/PowerShellHost.cs

Lines 150 to 167 in 5a03e37

	private static string[] GetEnabledPackageSources(ISourceRepositoryProvider sourceRepositoryProvider)
	{
	var enabledSources = sourceRepositoryProvider
	.GetRepositories()
	.Where(r => r.PackageSource.IsEnabled)
	.ToArray();
	var packageSources = new List<string>();
	if (enabledSources.Length > 1)
	{
	packageSources.Add(AggregateSourceName);
	}
	packageSources.AddRange(
	enabledSources.Select(r => r.PackageSource.Name));
	return packageSources.ToArray();
	}

I installed VS build from the PR and created ASP.NET C# MVC Application (Empty template) project, I noticed a popup window with null reference exception only for the first time.

It looks like a change was made to PowerShellHost.cs file in #4229 PR which was merged into dev 2 days ago. I am guessing this change is causing the test to fail in the VS PR.

https://github.com/NuGet/NuGet.Client/pull/4229/files#diff-6a61a5a4dcb437c8fb19e6189ca397aa926ae66e4442acbe9aab2e9ca896bb21R109-R113

PR Checklist

• PR has a meaningful title

• PR has a linked issue.

• Described changes

• Tests

  • N/A

• Documentation

  • N/A

[kartheekp-ms]

@aortiz-msft for approval.