Allow configuration of MAX_ATTEMPTS for tryScrollRecursively

[jleja]

Currently, MAX_ATTEMPTS is set locally on the add-on service with a value of 100. Which for most cases is fine, but I've run into a few instances where I need to try a few more times before the page is ready to be scrolled. Either setting this in environment/config.js or moving the value to inside of the service would make overriding this value a lot easier.