Add CreateAppCookieStickinessPolicy
LBCookieStickinessPolicy's CookieExpirationPeriod may not exist
Add CreateAppCookieStickinessPolicy
Add SetLoadBalancerPoliciesOfListener
Add SetLoadBalancerPoliciesForBackendServer (NOT TESTED YET)
Fix SetLoadBalancerPoliciesOfListener to send an empty list

When sending an empty list, we have to omit "member" part.