Attempt to install chromium as part of restore instead of running the CORS tests

One more go at https://github.com/aspnet/AspNetCore-Internal/issues/1619

src/Middleware/CORS/test/FunctionalTests/CORS.FunctionalTests.npmproj

@@ -12,5 +12,10 @@
     <IsTestProject>false</IsTestProject>
   </PropertyGroup>
 
+  <Target Name="InstallPuppeteer" BeforeTargets="Restore">
+    <!-- Explicitly install puppeteer. This will install the bundled Chromium as part of restore instead of as part of execution -->
+    <Exec Command="npm install puppeteer" />
+  </Target>
+
   <Import Project="$([MSBuild]::GetDirectoryNameOfFileAbove($(MSBuildThisFileDirectory), Directory.Build.targets))\Directory.Build.targets" />
 </Project>

src/Middleware/CORS/test/FunctionalTests/CorsMiddlewareFunctionalTest.cs

@@ -48,6 +48,8 @@ namespace FunctionalTests
                         Arguments = "test --no-watchman",
                     };
                 }
+                // Disallow the test from downloading \ installing chromium.
+                processStartInfo.Environment["PUPPETEER_SKIP_CHROMIUM_DOWNLOAD"] = "true";
 
                 // Act
                 var result = await ProcessManager.RunProcessAsync(processStartInfo, loggerFactory.CreateLogger("ProcessManager"));