message: gzip: add force load factory declaration
  Adds a force load factory declaration so that this filter can be force-loaded by Envoy Mobile.
  Risk Level: Low
  Testing: Done locally, and CI
  Docs Changes: None
  Release Notes: None
diff: @@ -26,6 +26,8 @@ private:
  Server::Configuration::FactoryContext& context) override;
  };
  +DECLARE_FACTORY(GzipFilterFactory);
  +
  } // namespace Gzip
  } // namespace HttpFilters
  } // namespace Extensions
  