FeatureFlags: omit metric when grafana cant run the feature (#51856) (#51981)

(cherry picked from commit 704a602d8c)

Co-authored-by: Stephanie Hingtgen <stephanie.hingtgen@grafana.com>

pkg/services/featuremgmt/manager.go

@@ -73,7 +73,8 @@ func (fm *FeatureManager) registerFlags(flags ...FeatureFlag) {
 	fm.update()
 }
 
-func (fm *FeatureManager) evaluate(ff *FeatureFlag) bool {
+// meetsRequirements checks if grafana is able to run the given feature due to dev mode or licensing requirements
+func (fm *FeatureManager) meetsRequirements(ff *FeatureFlag) bool {
 	if ff.RequiresDevMode && !fm.isDevMod {
 		return false
 	}
@@ -82,19 +83,22 @@ func (fm *FeatureManager) evaluate(ff *FeatureFlag) bool {
 		return false
 	}
 
-	// TODO: CEL - expression
-	return ff.Expression == "true"
+	return true
 }
 
 // Update
 func (fm *FeatureManager) update() {
 	enabled := make(map[string]bool)
 	for _, flag := range fm.flags {
-		val := fm.evaluate(flag)
+		// if grafana cannot run the feature, omit metrics around it
+		if !fm.meetsRequirements(flag) {
+			continue
+		}
 
 		// Update the registry
 		track := 0.0
-		if val {
+		// TODO: CEL - expression
+		if flag.Expression == "true" {
 			track = 1
 			enabled[flag.Name] = true
 		}