message: fix: Don't override metadata
diff: @@ -5,6 +5,7 @@ import { BrowserOptions, init as browserInit, SDK_VERSION } from '@sentry/browse
  */
  export function init(options: BrowserOptions): void {
  options._metadata = options._metadata || {};
  + if (options._metadata.sdk === undefined) {
  options._metadata.sdk = {
  name: 'sentry.javascript.react',
  packages: [
  @@ -15,5 +16,7 @@ export function init(options: BrowserOptions): void {
  ],
  version: SDK_VERSION,
  };
  + }
  +
  browserInit(options);
  }
  