I want to Java SDK to update one of the Product level attribute. I was going through the below documentation but need example for it https://commercetools.github.io/commercetools-sdk-java-v2/javadoc/com/commercetools/api/models/product/ProductSetAttributeInAllVariantsActionBuilder.html. Lets suppose I have one boolean attribute in product named "isAvailable" I want to update this as true/false. Please help me on it.