chore: updated comment for validator

internal/provider/validator_storagedirective.go

@@ -31,6 +31,9 @@ func (v stringIsStorageDirectiveValidator) ValidateMap(ctx context.Context, req
 	}
 
 	// If the value of any element is unknown or null, there is nothing to validate.
+	// Note tha the method is called twice by terraform. The first time it is called with
+	// unknown values, and the second time with known values.
+	// If the behavior changes, there is no need to validate all the values.
 	for _, element := range req.ConfigValue.Elements() {
 		if element.IsUnknown() || element.IsNull() {
 			return