LPS-41091 PortletPreferences are saved to global group instead of the actual Group

It is not valid to invoke the method PortalUtil.getScopeGroupId(request, portletId, true); from a portlet any more because it doesn't have access to the portal scope parameters such as doAsGroupId. Instead it needs to read this value from themeDisplay.
LPS-41690 it's no longer necessary to have custom logic to build portal-impl.jar