2.4.0 RC2 uses java worker version beam-master-20180228, should be 2.4.0 or beam-2.4.0

Running dataflow quickstart with the 2.4.0 RC2 uses a container named beam-master-20180228, should be 2.4.0 or beam-2.4.0, as in previous releases.

For 2.3.0, this version was set on the release branch with https://github.com/apache/beam/commit/245cb4cbec9c1dd7d4f9ff8eb3ab38667c5472e9#diff-0032670e9006c6eba52569423c64e6d2

Perhaps the release guide needs to be updated?

 wget https://repository.apache.org/content/repositories/orgapachebeam-1030/org/apache/beam/beam-runners-google-cloud-dataflow-java/2.4.0/beam-runners-google-cloud-dataflow-java-2.4.0.jar

jar xf beam-runners-google-cloud-dataflow-java-2.4.0.jar org/apache/beam/runners/dataflow/dataflow.properties

grep container.version org/apache/beam/runners/dataflow/dataflow.properties