Cloud Shell - August 17th, 2021 [Change]

## Change Cloud Code Extension updated to v1.13.1 Updates includes a simplified combined Kubernetes Explorer and GKE Explorer experience, Managed Cloud SDK performance improvements, as well as improved Cloud Run local development webview. Review the [Cloud Code release notes](https://github.com/GoogleCloudPlatform/cloud-code-vscode/blob/master/CHANGELOG.md#version-1131-july-2021) for a complete list of features/updates/bug fixes. ## Change Cloud Shell Editor is now built with Theia 1.16.0 Review the [Theia release notes](https://github.com/eclipse-theia/theia/blob/master/CHANGELOG.md#v1160---7292021) for a complete list of features/updates/bug fixes. ## Change Cloud Shell Editor Built-in Extensions Updated to 1.45.1 All built-in VS Code Extensions used by the Cloud Shell Editor have been updated to 1.45.1 to incorporate upstream changes. ## Change The Flutter SDK now comes preinstalled in Cloud Shell. Visit the [Flutter Docs](https://flutter.dev/docs) or simply enter `flutter` in Cloud Shell to get started. ## Change .Net 5.0 now comes preinstalled in Cloud Shell. Checkout the [dotnet-five](https://docs.microsoft.com/en-us/dotnet/core/dotnet-five) documentation for more details.