Refactor LB CIDR list comparison & rollback code

    - Replace manual null-check comparison with Objects.equals for clarity and null safety
    - Simplify CIDR list rollback to always restore backup value unconditionally
    - Add JavaDoc for setCidrList method for improved documentation

Author: CodeBleu

engine/schema/src/main/java/com/cloud/network/dao/LoadBalancerVO.java

@@ -145,6 +145,11 @@ public String toString() {
                         this, "id", "uuid", "name", "purpose", "state"));
     }
 
+    /**
+     *  Sets the CIDR list associated with this load balancer rule.
+     *
+     *  @param cidrList a comma-separated list of CIDR strings, e.g. "1.2.3.4/24,1.2.3.5/24" or and empty string e.g. "" to clear the restrictions
+     */
     public void setCidrList(String cidrList) {
         this.cidrList = cidrList;
     }

server/src/main/java/com/cloud/network/lb/LoadBalancingRulesManagerImpl.java

@@ -2306,9 +2306,6 @@ public LoadBalancer updateLoadBalancerRule(UpdateLoadBalancerRuleCmd cmd) {
                     if (lbBackup.getAlgorithm() != null) {
                         lb.setAlgorithm(lbBackup.getAlgorithm());
                     }
-                    if (lbBackup.getLbProtocol() != null) {
-                        lb.setLbProtocol(lbBackup.getLbProtocol());
-                    }
 
                     lb.setCidrList(lbBackup.getCidrList());
                     lb.setState(lbBackup.getState());