chore(codebuild): add forgotten rosetta fixture (aws#17129)

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packages/@aws-cdk/aws-codebuild/rosetta/default.ts-fixture

@@ -0,0 +1,19 @@
+// Fixture with packages imported, but nothing else
+import { Construct } from 'constructs';
+import { Stack, Duration, SecretValue } from '@aws-cdk/core';
+import codebuild = require('@aws-cdk/aws-codebuild');
+import iam = require('@aws-cdk/aws-iam');
+import ec2 = require('@aws-cdk/aws-ec2');
+import lambda = require('@aws-cdk/aws-lambda');
+import * as s3 from '@aws-cdk/aws-s3';
+import * as elbv2 from '@aws-cdk/aws-elasticloadbalancingv2';
+import * as ecr from '@aws-cdk/aws-ecr';
+import * as logs from '@aws-cdk/aws-logs';
+
+class Fixture extends Stack {
+  constructor(scope: Construct, id: string) {
+    super(scope, id);
+
+    /// here
+  }
+}