ASP.NET TargetManifestFiles should use $(SelfContained) property

[eerhardt]

See

MetaPackages/src/Microsoft.AspNetCore.All/build/PublishWithAspNetCoreTargetManifest.targets

Line 3 in 35ec069

<PublishWithAspNetCoreTargetManifest Condition="'$(PublishWithAspNetCoreTargetManifest)'=='' and '$(RuntimeIdentifier)'=='' and '$(RuntimeIdentifiers)'=='' and '$(PublishableProject)'=='true'">true</PublishWithAspNetCoreTargetManifest>

and

MetaPackages/src/Microsoft.AspNetCore.All/build/PublishWithAspNetCoreTargetManifest.targets

Line 19 in 35ec069

Condition="'$(RuntimeIdentifier)'!='' or '$(RuntimeIdentifiers)'!=''" />

These conditions shouldn't be using '$(RuntimeIdentifier)'=='' and '$(RuntimeIdentifiers)'=='', but instead it should use the new $(SelfContained) property instead.

In .NET Core 2.0, we now have a 3rd app model: Rid-specific, Shared Framework apps (sometimes referred to as a "low-fat app"). This means, I can publish an app that runs on the Shared Framework, but it only uses the win-x64 (or any other RID) assets. It isn't truly "portable" meaning it will run on any platform. This trims down on the size of the app, as it doesn't need to publish assets for other platforms that it won't run on. See dotnet/sdk#1053.

Thus, if someone tried publishing a Rid-specific, Shared Framework ASP.NET app and wanted to use the ASP.NET runtime store, these checks wouldn't be correct.

To fix this, simply change the RuntimeIdentifier checks to use SelfContained instead. Target manifest files shouldn't be used with SelfContained apps. But they should default to be used when the app isn't SelfContained.

/cc @JunTaoLuo @nguerrera