fix: add feature flag for domain sharding (#11797)

* fix: add feature flag for domain sharding

* fix review comment

* add comment for speical case

superset-frontend/src/utils/hostNamesConfig.js

@@ -16,6 +16,12 @@
  * specific language governing permissions and limitations
  * under the License.
  */
+import {
+  initFeatureFlags,
+  isFeatureEnabled,
+  FeatureFlag,
+} from 'src/featureFlags';
+
 function getDomainsConfig() {
   const appContainer = document.getElementById('app');
   if (!appContainer) {
@@ -23,8 +29,13 @@ function getDomainsConfig() {
   }
 
   const bootstrapData = JSON.parse(appContainer.getAttribute('data-bootstrap'));
+  // this module is a little special, it may be loaded before index.jsx,
+  // where window.featureFlags get initialized
+  // eslint-disable-next-line camelcase
+  initFeatureFlags(bootstrapData?.common?.feature_flags);
   const availableDomains = new Set([window.location.hostname]);
   if (
+    isFeatureEnabled(FeatureFlag.ALLOW_DASHBOARD_DOMAIN_SHARDING) &&
     bootstrapData &&
     bootstrapData.common &&
     bootstrapData.common.conf &&