build: run saucelabs and browserstack tests with ivy

We recently regressed when we switched to the auto-generated
SystemJS configuration in terms of how those legacy karma tests
run. Previously they ran with Ivy, but currently they run with view
engine. We should switch them back to Ivy since Ivy is the default in
version 9.

Author: devversion

tools/gulp/tasks/unit-test.ts

@@ -45,7 +45,7 @@ task(':test:build-system-config', () => {
   const configOutputPath = join(buildConfig.outputDir, 'karma-system-config.js');
   shelljs.cd(buildConfig.projectDir);
   const bazelGenfilesDir = shelljs.exec('yarn -s bazel info bazel-genfiles').stdout.trim();
-  shelljs.exec('yarn -s bazel build //test:system-config.js --config=view-engine');
+  shelljs.exec('yarn -s bazel build //test:system-config.js');
   shelljs.cp(join(bazelGenfilesDir, 'test/system-config.js'), configOutputPath);
   shelljs.chmod('u+w', configOutputPath);
 });