fix(codedeploy): DeploymentGroup's physical name not propagated to Application (#13582)

fixes #13337


----

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

Author: BLasan

packages/@aws-cdk/aws-codedeploy/lib/server/deployment-group.ts

@@ -269,7 +269,9 @@ export class ServerDeploymentGroup extends ServerDeploymentGroupBase {
       physicalName: props.deploymentGroupName,
     });
 
-    this.application = props.application || new ServerApplication(this, 'Application');
+    this.application = props.application || new ServerApplication(this, 'Application', {
+      applicationName: props.deploymentGroupName === cdk.PhysicalName.GENERATE_IF_NEEDED ? cdk.PhysicalName.GENERATE_IF_NEEDED : undefined,
+    });
 
     this.role = props.role || new iam.Role(this, 'Role', {
       assumedBy: new iam.ServicePrincipal('codedeploy.amazonaws.com'),

packages/@aws-cdk/aws-codedeploy/test/server/test.deployment-group.ts

@@ -1,4 +1,4 @@
-import { expect, haveResource, SynthUtils } from '@aws-cdk/assert';
+import { expect, haveOutput, haveResource, SynthUtils } from '@aws-cdk/assert';
 import * as autoscaling from '@aws-cdk/aws-autoscaling';
 import * as cloudwatch from '@aws-cdk/aws-cloudwatch';
 import * as ec2 from '@aws-cdk/aws-ec2';
@@ -28,6 +28,25 @@ export = {
       test.done();
     },
 
+    'creating an application with physical name if needed'(test: Test) {
+      const stack = new cdk.Stack(undefined, undefined, { env: { account: '12345', region: 'us-test-1' } });
+      const stack2 = new cdk.Stack(undefined, undefined, { env: { account: '12346', region: 'us-test-2' } });
+      const serverDeploymentGroup = new codedeploy.ServerDeploymentGroup(stack, 'MyDG', {
+        deploymentGroupName: cdk.PhysicalName.GENERATE_IF_NEEDED,
+      });
+
+      new cdk.CfnOutput(stack2, 'Output', {
+        value: serverDeploymentGroup.application.applicationName,
+      });
+
+      expect(stack2).to(haveOutput({
+        outputName: 'Output',
+        outputValue: 'defaultmydgapplication78dba0bb0c7580b32033',
+      }));
+
+      test.done();
+    },
+
     'can be imported'(test: Test) {
       const stack = new cdk.Stack();