MTFF: Allow viewers access in cloud (#114607)

* Reapply "K8s: read resource configs from API Enablement for API Builders" (#114475)

This reverts commit 4130bd9cd3.

* revert part that broke things

* FF service changes are gonna come later

* MTFF: allow viewers access to MTFF by enforcing runtime_config for custom routes

* unused var

* removed now

* pass the test, include defaults

* revert sample.ini change

pkg/tests/apis/features/features_test.go

@@ -22,9 +22,11 @@ func TestIntegrationFeatures(t *testing.T) {
 
 	// Enable a random flag -- check that it is reported as enabled
 	flag := featuremgmt.FlagGrafanaAPIServerWithExperimentalAPIs
+	// the test below tests using enable_api = true, without that, the runtime_config has been instructed to skip the API
 	helper := apis.NewK8sTestHelper(t, testinfra.GrafanaOpts{
-		AppModeProduction: true,
-		DisableAnonymous:  false, // allow anon user
+		OpenFeatureAPIEnabled: true,
+		AppModeProduction:     true,
+		DisableAnonymous:      false, // allow anon user
 		EnableFeatureToggles: []string{
 			flag, // used in test below
 		},