In dotnet new templates, only show "npm install" instruction when executing in CLI

Author: SteveSandersonMS

templates/package-builder/src/build/build.ts

@@ -203,6 +203,10 @@ function buildDotNetNewNuGetPackage(packageId: string) {
                     replaces: 'netcoreapp2.0',
                     defaultValue: 'netcoreapp2.0'
                 },
+                HostIdentifier: {
+                    type: 'bind',
+                    binding: 'HostIdentifier'
+                },
                 skipRestore: {
                     type: 'parameter',
                     datatype: 'bool',
@@ -236,6 +240,7 @@ function buildDotNetNewNuGetPackage(packageId: string) {
                     // For the preview2 release, just display manual instructions instead.
                     // This is only applicable on the command line, because VS will restore
                     // NPM packages automatically by default.
+                    condition: '(HostIdentifier == "dotnetcli" || HostIdentifier == "dotnetcli-preview")',
                     actionId: 'AC1156F7-BB77-4DB8-B28F-24EEBCCA1E5C',
                     description: '\n\n-------------------------------------------------------------------\nIMPORTANT: Before running this project on the command line,\n           you must restore NPM packages by running "npm install"\n-------------------------------------------------------------------\n',
                     manualInstructions: [{ text: 'Run "npm install"' }]