message: build(aio): fix plunker for custom plunkers
  PR Close
diff: @@ -152,6 +152,7 @@ class PlunkerBuilder {
  // Matches main.ts or main.1.ts
  if (/^main(?:[.-]\w+)?\.ts$/.test(relativeFileName)) {
  content = fileTranslator.translate(content, mainTsRules);
  + relativeFileName = 'main.ts';
  }
  if (relativeFileName == 'systemjs.config.extras.js') {
  