Cloud Shell - June 29th, 2022 [Change]

## Change Cloud Code Extension updated to 1.18.3 Update includes a new and improved Kubernetes development experience with the Development Sessions Explorer, support for private clusters, a refreshed welcome page, and more! Review the [Cloud Code release notes](https://github.com/GoogleCloudPlatform/cloud-code-vscode/blob/master/CHANGELOG.md#version-1183-may-2022) for a complete list of features, updates, and fixes. ## Change Cloud Shell Editor is built with Theia 1.25.0 Review the [Theia release notes](https://github.com/eclipse-theia/theia/blob/master/CHANGELOG.md#v1250---4282022) for a complete list of features/updates/bug fixes. ## Change Cloud Shell now defaults to Python 3 Python 2 is still included as a development tool in Cloud Shell and may be invoked using `python2`.