Serve the server pem with GET requests.

def do_GET(self):  # pylint: disable=g-bad-name
    """Serve the server pem with GET requests."""
    self._IncrementActiveCount()
    try:
      if self.path.startswith("/server.pem"):
        stats_collector_instance.Get().IncrementCounter(
            "frontend_http_requests", fields=["cert", "http"])
        self.ServerPem()
      elif self.path.startswith(self.static_content_path):
        stats_collector_instance.Get().IncrementCounter(
            "frontend_http_requests", fields=["static", "http"])
        self.ServeStatic(self.path[len(self.static_content_path):])
    finally:
      self._DecrementActiveCount()