fix feature flag module import

Author: srarkar

packages/db-service/src/app.module.ts

@@ -13,6 +13,7 @@ import { FileBucketModule } from './modules/file_bucket/file_bucket.module';
 import { FileConfigModule } from './modules/file_config/file_config.module';
 import { FileProviderModule } from './modules/file_provider/file_provider.module';
 import { AnalyticsConfigModule } from './modules/analytics_config/analytics_config.module';
+import { FeatureFlagModule } from './modules/feature_flag/feature_flag.module';
 
 @Module({
   imports: [