[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.
I mean, without settings 'YARNAlpha' and 'YARNStable', (leave only  YARNCommon setting). we can run scalastyle successfully but fail to build with 'sbt/sbt assembly'.
Without this patch, of course, we can build successfully.