Make sure Java Apache Beam Logs properly include step names.

I've noticed that the DataflowWorkerLoggingHandler grabs the current execution state and extracts the step name from it.

However, in the Java SDK

ExecutionState does not implement step names, I left that logic only in DataflowExecutionState and omitted it from the base class. Thus when the Java SDK uses its SimpleExecutionState, it will not receive these step names and log them properly.

@swegner, can you confirm that this is the behaviour we want, for Java Beam SDKs to also include their step name in the logs, as used by the DatafloWorkerLoggingHandler? Java SDK code will end up using this handler as well, in portability?

https://github.com/apache/beam/blob/52e73282223980fc0df9fbdbeddb2abb24d6600e/runners/google-cloud-dataflow-java/worker/src/main/java/org/apache/beam/runners/dataflow/worker/logging/DataflowWorkerLoggingHandler.java#L148

Also, it may matter for dataflow the specific type of step name being used. (initial, optomized, user name ,etc.). The full name context will definetly not be available in the beam java SDK,