fix(codebuild): take the account & region of an imported Project from its ARN (#13708)

This is needed to correctly use CodeBuild in CodePipeline
(which needs to know whether the Project is from a different account/region).

Fixes #13694

----

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

Author: skinny85

packages/@aws-cdk/aws-codebuild/lib/project.ts

@@ -639,14 +639,19 @@ export interface BindToCodePipelineOptions {
 export class Project extends ProjectBase {
 
   public static fromProjectArn(scope: Construct, id: string, projectArn: string): IProject {
+    const parsedArn = Stack.of(scope).parseArn(projectArn);
+
     class Import extends ProjectBase {
       public readonly grantPrincipal: iam.IPrincipal;
       public readonly projectArn = projectArn;
-      public readonly projectName = Stack.of(scope).parseArn(projectArn).resourceName!;
+      public readonly projectName = parsedArn.resourceName!;
       public readonly role?: iam.Role = undefined;
 
       constructor(s: Construct, i: string) {
-        super(s, i);
+        super(s, i, {
+          account: parsedArn.account,
+          region: parsedArn.region,
+        });
         this.grantPrincipal = new iam.UnknownPrincipal({ resource: this });
       }
     }

packages/@aws-cdk/aws-codebuild/test/test.project.ts

@@ -1386,6 +1386,7 @@ export = {
 
       test.done();
     },
+
     'can override build timeout'(test: Test) {
       // GIVEN
       const stack = new cdk.Stack();
@@ -1407,4 +1408,18 @@ export = {
       test.done();
     },
   },
+
+  'can be imported': {
+    'by ARN'(test: Test) {
+      const stack = new cdk.Stack();
+      const project = codebuild.Project.fromProjectArn(stack, 'Project',
+        'arn:aws:codebuild:us-west-2:123456789012:project/My-Project');
+
+      test.equal(project.projectName, 'My-Project');
+      test.equal(project.env.account, '123456789012');
+      test.equal(project.env.region, 'us-west-2');
+
+      test.done();
+    },
+  },
 };