Redact sensitive values from config in health data (#12421)

The health api returns the server configuration details. Redact
sensitive values from the config values like URLs and credentials.

internal/config/help.go

@@ -25,6 +25,10 @@ type HelpKV struct {
 	Description string `json:"description"`
 	Optional    bool   `json:"optional"`
 
+	// Indicates if the value contains sensitive info
+	// that shouldn't be exposed in certain apis
+	Sensitive bool `json:"sensitive"`
+
 	// Indicates if sub-sys supports multiple targets.
 	MultipleTargets bool `json:"multipleTargets"`
 }