Create example for Apache Beam

The Apache Beam example referenced by the online doc is in [old repository](https://github.com/aws-samples/amazon-kinesis-data-analytics-examples/tree/master/Beam) and apache beam version is old.
I would like to contribute by creating an example in this repository so that users can refer to current settings of Apache Beam.

[Download and examine the application code](https://docs.aws.amazon.com/managed-flink/latest/java/examples-beam.html#examples-beam-download)

Start by reviewing the linked online documentation and the existing Beam example in the old repository. Compare its Apache Beam version and settings with the current repository conventions, then create a corresponding example here and verify that the documentation link can point users to it.

Written by the indexing model from the issue text.