App Engine Java 11 support

(Please ensure you are running the latest version of Cloud Cloud for IntelliJ with _Help > Check for Updates_.)

- Cloud Code for IntelliJ version: IntelliJ Ultimate
- OS: macOS Mojave

**What did you do?**

Would like to deploy a JAR-packaged up into App Engine Java 11

**What did you expect to see?**

In Cloud Code, options to automatically configure, add app.yaml, and configure plugins.

**What did you see instead?**

Popup to deploy to App Engine Flexible.