chore(discover): Make feature handler flagpole strategy (#74941)

Make it a flagpole strategy for now for bug bash,
will add a feature handler in getsentry to enable it
on s4s in a follow up

src/sentry/features/temporary.py

@@ -243,7 +243,7 @@ def register_temporary_features(manager: FeatureManager):
     manager.add("organizations:performance-database-view-percentiles", OrganizationFeature, FeatureHandlerStrategy.REMOTE, api_expose=False)
     manager.add("organizations:performance-db-main-thread-detector", OrganizationFeature, api_expose=False)
     # Enable Discover Saved Query dataset selector
-    manager.add("organizations:performance-discover-dataset-selector", OrganizationFeature, FeatureHandlerStrategy.REMOTE, api_expose=True)
+    manager.add("organizations:performance-discover-dataset-selector", OrganizationFeature, FeatureHandlerStrategy.FLAGPOLE, api_expose=True)
     # Enable backend overriding and always making a fresh split decision
     manager.add("organizations:performance-discover-widget-split-override-save", OrganizationFeature, FeatureHandlerStrategy.REMOTE, api_expose=False)
     # Enable UI sending a discover split for widget