plugins: refactory to use default export for new backend system

Co-authored-by: Fredrik Adelöw <freben@gmail.com>
Co-authored-by: Camila Belo <camilaibs@gmail.com>
Co-authored-by: Johan Haals <johan.haals@gmail.com>
Co-authored-by: Philipp Hugenroth <philipph@spotify.com>
Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

plugins/proxy-backend/api-report.md

@@ -13,7 +13,8 @@ import { PluginEndpointDiscovery } from '@backstage/backend-common';
 export function createRouter(options: RouterOptions): Promise<express.Router>;
 
 // @alpha
-export const proxyPlugin: () => BackendFeature;
+const proxyPlugin: () => BackendFeature;
+export default proxyPlugin;
 
 // @public (undocumented)
 export interface RouterOptions {

plugins/proxy-backend/src/index.ts

@@ -21,4 +21,4 @@
  */
 
 export * from './service';
-export { proxyPlugin } from './plugin';
+export { proxyPlugin as default } from './plugin';