fix(remote-config, other): return proper error for onConfigUpdated

previously was not a correctly formatted error object and not thrown
simply returned - e2e test was probing it incorrectly so this slipped
through despite a lot of attention!

Author: mikehardy

packages/remote-config/e2e/config.e2e.js

@@ -786,6 +786,7 @@ describe('remoteConfig()', function () {
         const { getRemoteConfig, onConfigUpdated } = remoteConfigModular;
         try {
           onConfigUpdated(getRemoteConfig());
+          throw new Error('Did not reject');
         } catch (error) {
           error.message.should.containEql(
             "'listenerOrObserver' expected a function or an object with 'next' function.",
@@ -804,7 +805,9 @@ describe('remoteConfig()', function () {
         const { getRemoteConfig, onConfigUpdated } = remoteConfigModular;
         try {
           onConfigUpdated(getRemoteConfig(), () => {});
+          throw new Error('Did not reject');
         } catch (error) {
+          error.code.should.equal('unsupported');
           error.message.should.containEql('Not supported by the Firebase Javascript SDK');
         }
       });

packages/remote-config/lib/web/RNFBConfigModule.js

@@ -122,6 +122,9 @@ export default {
     });
   },
   onConfigUpdated() {
-    return getWebError('unsupported', 'Not supported by the Firebase Javascript SDK.');
+    throw getWebError({
+      code: 'unsupported',
+      message: 'Not supported by the Firebase Javascript SDK.',
+    });
   },
 };