YARN-7355. TestDistributedShell should be scheduler agnostic. (Contributed by Haibo)

(cherry picked from commit 6b7c87c94592606966a4229313b3d0da48f16158)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-distributedshell/src/test/java/org/apache/hadoop/yarn/applications/distributedshell/TestDistributedShell.java

@@ -149,7 +149,6 @@ public class TestDistributedShell {
     conf.setBoolean(YarnConfiguration.SYSTEM_METRICS_PUBLISHER_ENABLED, true);
 
     conf.set(YarnConfiguration.NM_VMEM_PMEM_RATIO, "8");
-    conf.set(YarnConfiguration.RM_SCHEDULER, CapacityScheduler.class.getName());
     conf.setBoolean(YarnConfiguration.NODE_LABELS_ENABLED, true);
     conf.set("mapreduce.jobhistory.address",
         "0.0.0.0:" + ServerSocketUtil.getPort(10021, 10));