[AURON #1442] Fix FileNotFoundException in BuildinfoInSparkUISuite by properly configuring temp event log dir

[yew1eb]

Which issue does this PR close?

Closes #1442 .

Rationale for this change

The original beforeAll() called super.beforeAll() first, which initializes the SparkSession (and thus the SparkContext). Spark’s EventLoggingListener starts during SparkContext construction and immediately validates spark.eventLog.dir.
The subsequent line val eventLogDir = Utils.createTempDir("/tmp/spark-events") creates the directory after the listener has already failed with:

An exception or error caused a run to abort: File file:/private/tmp/spark-events does not exist 
java.io.FileNotFoundException: File file:/private/tmp/spark-events does not exist
	at org.apache.hadoop.fs.RawLocalFileSystem.deprecatedGetFileStatus(RawLocalFileSystem.java:980)
	at org.apache.hadoop.fs.RawLocalFileSystem.getFileLinkStatusInternal(RawLocalFileSystem.java:1301)
	at org.apache.hadoop.fs.RawLocalFileSystem.getFileStatus(RawLocalFileSystem.java:970)
	at org.apache.hadoop.fs.FilterFileSystem.getFileStatus(FilterFileSystem.java:462)
	at org.apache.spark.deploy.history.EventLogFileWriter.requireLogBaseDirAsDirectory(EventLogFileWriters.scala:77)
	at org.apache.spark.deploy.history.SingleEventLogFileWriter.start(EventLogFileWriters.scala:221)
	at org.apache.spark.scheduler.EventLoggingListener.start(EventLoggingListener.scala:83)
	at org.apache.spark.SparkContext.<init>(SparkContext.scala:622)

This PR creates a proper temporary directory before the SparkSession is initialized, configures it via sparkConf, and cleans it up afterward.

What changes are included in this PR?

Are there any user-facing changes?

No.

How was this patch tested?

Verified the test passed.

[merrily01]

Thanks @yew1eb