[AURON #2137] Native thread name appends the original thread name (#2144)

# Which issue does this PR close?

Closes #2137

# Rationale for this change

# What changes are included in this PR?

# Are there any user-facing changes?

# How was this patch tested?

spark-extension/src/main/scala/org/apache/spark/sql/auron/util/TaskContextHelper.scala

diff --git a/spark-extension/src/main/scala/org/apache/spark/sql/auron/util/TaskContextHelper.scala b/spark-extension/src/main/scala/org/apache/spark/sql/auron/util/TaskContextHelper.scala
index 8e5d735..309139e 100644
--- a/spark-extension/src/main/scala/org/apache/spark/sql/auron/util/TaskContextHelper.scala
+++ b/spark-extension/src/main/scala/org/apache/spark/sql/auron/util/TaskContextHelper.scala
@@ -45,12 +45,13 @@
   def setNativeThreadName(): Unit = {
     val context: TaskContext = TaskContext.get()
     val thread = Thread.currentThread()
-    val threadName = if (context != null) {
+    val threadPrefix = if (context != null) {
       s"auron native task ${context.partitionId()}.${context.attemptNumber()} in stage ${context
         .stageId()}.${context.stageAttemptNumber()} (TID ${context.taskAttemptId()})"
     } else {
-      "auron native task " + thread.getName
+      "auron native task"
     }
+    val threadName = threadPrefix + " " + thread.getName
     thread.setName(threadName)
   }