[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.
Only for scalastyle, settings for alpha and stable are not needed but if we don't set those settings, we cannot build because the sources in common cannot resolve reference to the sources in alpha and stable.