[release/5.0] Exclude locally-built packages from smoke-test-prereqs. (#2382)

* Exclude locally-built packages from smoke-test-prereqs.
This makes two changes to prevent our locally-built packages from making it into the smoke-test-prereqs tarball:
- Remove any packages cached in the system cache after we copy it to our local NuGet cache (so we get the credential plugin).
- Don't copy packages to the prereqs directory after the local tests (which can restore locally-built packages).

This accomplishes two things:
- Smoke-testing will be more true to the partner and user experience (using the official packages that a developer would restore when actually using the product).
- The official packages will include all TFMs and runtimes so the smoke-test-prereqs tarball will be universal across all of our builds.

* Enable online tests for CI smoke-tests.

Author: crummel

build.proj

@@ -153,7 +153,6 @@
   <Target Name="RunSmokeTest" DependsOnTargets="GetProdConBlobFeedUrl">
     <PropertyGroup>
       <SmokeTestCommand>./smoke-test.sh</SmokeTestCommand>
-      <SmokeTestCommand>$(SmokeTestCommand) --minimal</SmokeTestCommand>
       <SmokeTestCommand>$(SmokeTestCommand) --projectOutput</SmokeTestCommand>
       <SmokeTestCommand>$(SmokeTestCommand) --configuration $(Configuration)</SmokeTestCommand>
       <SmokeTestCommand>$(SmokeTestCommand) --archiveRestoredPackages</SmokeTestCommand>

smoke-test.sh

@@ -560,6 +560,8 @@ function resetCaches() {
     # Copy NuGet plugins if running user has HOME and we have auth. In particular, the auth plugin.
     if [ "${internalPackageFeedPat:-}" ] && [ "${executingUserHome:-}" ]; then
         cp -r "$executingUserHome/.nuget/" "$HOME/.nuget/" || :
+        # remove cached packages if there were any
+        rm -rf "$HOME/.nuget/packages"
     fi
 }
 
@@ -650,7 +652,6 @@ if [ "$excludeLocalTests" == "false" ]; then
     fi
     echo "RUN ALL TESTS - LOCAL RESTORE SOURCE"
     runAllTests
-    copyRestoredPackages
     echo "LOCAL RESTORE SOURCE - ALL TESTS PASSED!"
 fi