Array out of bounds exception on HtmlPolicyBuilder initialization

[mymhealthltd-joshengland]

Constructing a HtmlPolicyBuilder zero-defined global attributes, globally, leads to an Arry out of bounds exception

Here is sample code that produces the problem

new HtmlPolicyBuilder().allowElements().allowAttributes().globally().toFactory();

The exception comes form an un-guarded check on the zeroth element of the attributesNames list. In this situation, attribute names is empty and so has no zeroth element.

    public HtmlPolicyBuilder globally() {
      if(attributeNames.get(0).equals("style")) {
        return allowStyling();
      } else {
        return HtmlPolicyBuilder.this.allowAttributesGlobally(
            policy, attributeNames);
      }
    }

This construction used to work in version 20180219.1 of this library but is broken in 20211018.2.