[SPARK-3677] [BUILD] [YARN] pom.xml and SparkBuild.scala are wrong : Scalastyle is never applied to the sources under yarn/common

When we run "sbt -Pyarn scalastyle" or "mvn package", scalastyle is not applied to the sources under yarn/common.
You mean without YARNAlpha and YARNStable changes of this patch I can not build assembly ? Interesting, can you remove those changes from the patch and let me see the errors jenkins report.