Add dropdown-rename-icon 

## dropdown-rename-icon [(#4147)](https://github.com/patternfly/patternfly-react/pull/4147)
- [ ] Remove dropdownItemIcon in favor of `<DropdownItem icon={<Icon />} />`
- [ ] Remove variant prop from DropdownItem. If you were using variant="icon" before, use the new icon prop instead. (might need to split this into new rule)
