[SPARK-31484][CORE][FLOLLOWUP] Use taskAttemptId in checkpoint filename

### What changes were proposed in this pull request?

As suggested by apache#28255 (comment), this patch proposes to use taskAttemptId in checkpoint filename, instead of stageAttemptNumber + attemptNumber.

### Why are the changes needed?

To simplify checkpoint simplified and unique.

### Does this PR introduce any user-facing change?

No

### How was this patch tested?

Existing tests.

Closes apache#28289 from viirya/SPARK-31484-followup.

Authored-by: Liang-Chi Hsieh <[email protected]>
Signed-off-by: HyukjinKwon <[email protected]>

Author: viirya

core/src/main/scala/org/apache/spark/rdd/ReliableCheckpointRDD.scala

@@ -199,8 +199,7 @@ private[spark] object ReliableCheckpointRDD extends Logging {
 
     val finalOutputName = ReliableCheckpointRDD.checkpointFileName(ctx.partitionId())
     val finalOutputPath = new Path(outputDir, finalOutputName)
-    val tempOutputPath = new Path(outputDir,
-      s".$finalOutputName-attempt-${ctx.stageAttemptNumber()}-${ctx.attemptNumber()}")
+    val tempOutputPath = new Path(outputDir, s".$finalOutputName-attempt-${ctx.taskAttemptId()}")
 
     val bufferSize = env.conf.get(BUFFER_SIZE)