feat(elasticloadbalancingv2): client keepalive for ALB (#29504)

### Issue # (if applicable)

Closes #29503.

### Reason for this change

[ALB supports configuring client keepalive duration](https://aws.amazon.com/jp/about-aws/whats-new/2024/03/application-load-balancer-http-keepalive-duration/) but AWS CDK cannot do that.

### Description of changes

Add `clientKeepAlive` properties to `ApplicationLoadBalancerProps`.

```ts
      new elbv2.ApplicationLoadBalancer(stack, 'LB', {
        vpc,
        clientKeepAlive: Duration.seconds(250),
      });
```

### Description of how you validated changes

I've added both integ and unit tests

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk-testing/framework-integ/test/aws-elasticloadbalancingv2/test/integ.alb.attributes.js.snapshot/aws-cdk-elbv2-integ.template.json

@@ -18,9 +18,6 @@
   "VPCPublicSubnet1SubnetB4246D30": {
    "Type": "AWS::EC2::Subnet",
    "Properties": {
-    "VpcId": {
-     "Ref": "VPCB9E5F0B4"
-    },
     "AvailabilityZone": {
      "Fn::Select": [
       0,
@@ -44,21 +41,24 @@
       "Key": "Name",
       "Value": "aws-cdk-elbv2-integ/VPC/PublicSubnet1"
      }
-    ]
+    ],
+    "VpcId": {
+     "Ref": "VPCB9E5F0B4"
+    }
    }
   },
   "VPCPublicSubnet1RouteTableFEE4B781": {
    "Type": "AWS::EC2::RouteTable",
    "Properties": {
-    "VpcId": {
-     "Ref": "VPCB9E5F0B4"
-    },
     "Tags": [
      {
       "Key": "Name",
       "Value": "aws-cdk-elbv2-integ/VPC/PublicSubnet1"
      }
-    ]
+    ],
+    "VpcId": {
+     "Ref": "VPCB9E5F0B4"
+    }
    }
   },
   "VPCPublicSubnet1RouteTableAssociation0B0896DC": {
@@ -75,12 +75,12 @@
   "VPCPublicSubnet1DefaultRoute91CEF279": {
    "Type": "AWS::EC2::Route",
    "Properties": {
-    "RouteTableId": {
-     "Ref": "VPCPublicSubnet1RouteTableFEE4B781"
-    },
     "DestinationCidrBlock": "0.0.0.0/0",
     "GatewayId": {
      "Ref": "VPCIGWB7E252D3"
+    },
+    "RouteTableId": {
+     "Ref": "VPCPublicSubnet1RouteTableFEE4B781"
     }
    },
    "DependsOn": [
@@ -102,15 +102,15 @@
   "VPCPublicSubnet1NATGatewayE0556630": {
    "Type": "AWS::EC2::NatGateway",
    "Properties": {
-    "SubnetId": {
-     "Ref": "VPCPublicSubnet1SubnetB4246D30"
-    },
     "AllocationId": {
      "Fn::GetAtt": [
       "VPCPublicSubnet1EIP6AD938E8",
       "AllocationId"
      ]
     },
+    "SubnetId": {
+     "Ref": "VPCPublicSubnet1SubnetB4246D30"
+    },
     "Tags": [
      {
       "Key": "Name",
@@ -126,9 +126,6 @@
   "VPCPublicSubnet2Subnet74179F39": {
    "Type": "AWS::EC2::Subnet",
    "Properties": {
-    "VpcId": {
-     "Ref": "VPCB9E5F0B4"
-    },
     "AvailabilityZone": {
      "Fn::Select": [
       1,
@@ -152,21 +149,24 @@
       "Key": "Name",
       "Value": "aws-cdk-elbv2-integ/VPC/PublicSubnet2"
      }
-    ]
+    ],
+    "VpcId": {
+     "Ref": "VPCB9E5F0B4"
+    }
    }
   },
   "VPCPublicSubnet2RouteTable6F1A15F1": {
    "Type": "AWS::EC2::RouteTable",
    "Properties": {
-    "VpcId": {
-     "Ref": "VPCB9E5F0B4"
-    },
     "Tags": [
      {
       "Key": "Name",
       "Value": "aws-cdk-elbv2-integ/VPC/PublicSubnet2"
      }
-    ]
+    ],
+    "VpcId": {
+     "Ref": "VPCB9E5F0B4"
+    }
    }
   },
   "VPCPublicSubnet2RouteTableAssociation5A808732": {
@@ -183,12 +183,12 @@
   "VPCPublicSubnet2DefaultRouteB7481BBA": {
    "Type": "AWS::EC2::Route",
    "Properties": {
-    "RouteTableId": {
-     "Ref": "VPCPublicSubnet2RouteTable6F1A15F1"
-    },
     "DestinationCidrBlock": "0.0.0.0/0",
     "GatewayId": {
      "Ref": "VPCIGWB7E252D3"
+    },
+    "RouteTableId": {
+     "Ref": "VPCPublicSubnet2RouteTable6F1A15F1"
     }
    },
    "DependsOn": [
@@ -210,15 +210,15 @@
   "VPCPublicSubnet2NATGateway3C070193": {
    "Type": "AWS::EC2::NatGateway",
    "Properties": {
-    "SubnetId": {
-     "Ref": "VPCPublicSubnet2Subnet74179F39"
-    },
     "AllocationId": {
      "Fn::GetAtt": [
       "VPCPublicSubnet2EIP4947BC00",
       "AllocationId"
      ]
     },
+    "SubnetId": {
+     "Ref": "VPCPublicSubnet2Subnet74179F39"
+    },
     "Tags": [
      {
       "Key": "Name",
@@ -234,9 +234,6 @@
   "VPCPrivateSubnet1Subnet8BCA10E0": {
    "Type": "AWS::EC2::Subnet",
    "Properties": {
-    "VpcId": {
-     "Ref": "VPCB9E5F0B4"
-    },
     "AvailabilityZone": {
      "Fn::Select": [
       0,
@@ -260,21 +257,24 @@
       "Key": "Name",
       "Value": "aws-cdk-elbv2-integ/VPC/PrivateSubnet1"
      }
-    ]
+    ],
+    "VpcId": {
+     "Ref": "VPCB9E5F0B4"
+    }
    }
   },
   "VPCPrivateSubnet1RouteTableBE8A6027": {
    "Type": "AWS::EC2::RouteTable",
    "Properties": {
-    "VpcId": {
-     "Ref": "VPCB9E5F0B4"
-    },
     "Tags": [
      {
       "Key": "Name",
       "Value": "aws-cdk-elbv2-integ/VPC/PrivateSubnet1"
      }
-    ]
+    ],
+    "VpcId": {
+     "Ref": "VPCB9E5F0B4"
+    }
    }
   },
   "VPCPrivateSubnet1RouteTableAssociation347902D1": {
@@ -291,21 +291,18 @@
   "VPCPrivateSubnet1DefaultRouteAE1D6490": {
    "Type": "AWS::EC2::Route",
    "Properties": {
-    "RouteTableId": {
-     "Ref": "VPCPrivateSubnet1RouteTableBE8A6027"
-    },
     "DestinationCidrBlock": "0.0.0.0/0",
     "NatGatewayId": {
      "Ref": "VPCPublicSubnet1NATGatewayE0556630"
+    },
+    "RouteTableId": {
+     "Ref": "VPCPrivateSubnet1RouteTableBE8A6027"
     }
    }
   },
   "VPCPrivateSubnet2SubnetCFCDAA7A": {
    "Type": "AWS::EC2::Subnet",
    "Properties": {
-    "VpcId": {
-     "Ref": "VPCB9E5F0B4"
-    },
     "AvailabilityZone": {
      "Fn::Select": [
       1,
@@ -329,21 +326,24 @@
       "Key": "Name",
       "Value": "aws-cdk-elbv2-integ/VPC/PrivateSubnet2"
      }
-    ]
+    ],
+    "VpcId": {
+     "Ref": "VPCB9E5F0B4"
+    }
    }
   },
   "VPCPrivateSubnet2RouteTable0A19E10E": {
    "Type": "AWS::EC2::RouteTable",
    "Properties": {
-    "VpcId": {
-     "Ref": "VPCB9E5F0B4"
-    },
     "Tags": [
      {
       "Key": "Name",
       "Value": "aws-cdk-elbv2-integ/VPC/PrivateSubnet2"
      }
-    ]
+    ],
+    "VpcId": {
+     "Ref": "VPCB9E5F0B4"
+    }
    }
   },
   "VPCPrivateSubnet2RouteTableAssociation0C73D413": {
@@ -360,12 +360,12 @@
   "VPCPrivateSubnet2DefaultRouteF4F5CFD2": {
    "Type": "AWS::EC2::Route",
    "Properties": {
-    "RouteTableId": {
-     "Ref": "VPCPrivateSubnet2RouteTable0A19E10E"
-    },
     "DestinationCidrBlock": "0.0.0.0/0",
     "NatGatewayId": {
      "Ref": "VPCPublicSubnet2NATGateway3C070193"
+    },
+    "RouteTableId": {
+     "Ref": "VPCPrivateSubnet2RouteTable0A19E10E"
     }
    }
   },
@@ -383,11 +383,11 @@
   "VPCVPCGW99B986DC": {
    "Type": "AWS::EC2::VPCGatewayAttachment",
    "Properties": {
-    "VpcId": {
-     "Ref": "VPCB9E5F0B4"
-    },
     "InternetGatewayId": {
      "Ref": "VPCIGWB7E252D3"
+    },
+    "VpcId": {
+     "Ref": "VPCB9E5F0B4"
     }
    }
   },
@@ -414,6 +414,10 @@
      {
       "Key": "routing.http.desync_mitigation_mode",
       "Value": "defensive"
+     },
+     {
+      "Key": "client_keep_alive.seconds",
+      "Value": "1000"
      }
     ],
     "Scheme": "internet-facing",