Local Activity asynchronously started at the end of the workflow implementation leads to failure

[Spikhalskiy]

Expected Behavior

    @Override
    public void wofklowMethod() {
      Async.procedure(activity::execute);
    }

An activity scheduled at the end of the workflow code asynchronously without waiting on the promise should be ignored. Alternatively, it may be executed. Such a code shouldn't block workflow completion, it's not an invalid workflow implementation.

Actual Behavior

It leads to io.grpc.StatusRuntimeException: NOT_FOUND: workflow execution already completed exception on worker with workflow never completing.

Steps to Reproduce the Problem

Unit test: https://github.com/Spikhalskiy/java-sdk/commit/718fe8e794a50188c639e79a6ee47576960ae353

[bergundy]

@Spikhalskiy please add to sdk features. Not 100% sure we put it there

[Spikhalskiy]

Related to #1722