[release/3.0] Switch to embedded package icon

[wtgodbe]

Contributes to aspnet/AspNetCore-Internal#3103

[wtgodbe]

F:\workspace_work\1\s.dotnet\sdk\3.0.100-preview8-013656\Sdks\NuGet.Build.Tasks.Pack\buildCrossTargeting\NuGet.Build.Tasks.Pack.targets(198,5): error : The element 'metadata' in namespace 'http://schemas.microsoft.com/packaging/2012/06/nuspec.xsd' has invalid child element 'icon' in namespace 'http://schemas.microsoft.com/packaging/2012/06/nuspec.xsd'. List of possible elements expected: 'language, summary, references, contentFiles, iconUrl, releaseNotes, packageTypes, dependencies, owners, frameworkReferences, licenseUrl, frameworkAssemblies, title' in namespace 'http://schemas.microsoft.com/packaging/2012/06/nuspec.xsd'. This validation error occurred in a 'icon' element. [F:\workspace_work\1\s\src\Razor\src\Microsoft.NET.Sdk.Razor\Microsoft.NET.Sdk.Razor.csproj]

This branch has the same SDK version as other release/3.0 branches in ASP-land, so I'm not sure why this only happens for the Razor project - @dougbu @JunTaoLuo looks like we might be using a custom SDK there?

[JunTaoLuo]

We originally pinned the SDK to preview8 to avoid the PackageIcon issue. Now that we're reacting to it, we probably need a new SDK that recognizes the icon element in the nuspec.

[wtgodbe]

Just updated to the GA SDK

[wtgodbe]

Lots of CS1508's popping up with the GA SDK, such as:

CSC : error CS1508: Resource identifier 'AspNetCore.TestFiles_IntegrationTests_CodeGenerationIntegrationTest_RazorPagesWithRouteTemplate' has already been used in this assembly [/Users/vsts/agent/2.155.1/work/1/s/src/Razor/test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Version2_X.Test/Microsoft.AspNetCore.Mvc.Razor.Extensions.Version2_X.Test.csproj]

Seeing the same thing in dotnet/ef6#1291 (comment)

[wtgodbe]

@rynowak do I need to do something similar to 4eb9386?

[pranavkm]

Good to go

[wtgodbe]

Thanks @pranavkm!

[wtgodbe]

Don't merge until #1168 is in