Replace isArray helper with native Array.isArray

src/html/htmlReporterUtils.js

@@ -5,7 +5,7 @@ jasmineRequire.htmlReporterUtils = function(j$) {
     const el = document.createElement(type);
     let children;
 
-    if (j$.private.isArray(childrenArrayOrVarArgs)) {
+    if (Array.isArray(childrenArrayOrVarArgs)) {
       children = childrenArrayOrVarArgs;
     } else {
       children = [];