Workflow examples are wrong for Java

[kaibocai]

Describe the issue

The Task chaining, Fan-out/fan-in, External system interaction workflow Java examples are not correct.

URL of the docs

Task chaining: https://docs.dapr.io/developing-applications/building-blocks/workflow/workflow-patterns/#task-chaining
Fan-out/fan-in: https://docs.dapr.io/developing-applications/building-blocks/workflow/workflow-patterns/#fan-outfan-in
External system interaction: https://docs.dapr.io/developing-applications/building-blocks/workflow/workflow-patterns/#external-system-interaction
Expected content

The Java example code should match the same logics in Python and Dotnet, but they are not.

Screenshots

Take the Task chaining as an example, the below example code didn't show the correct logic.

Additional context