[MINOR][PYTHON] Use a helper in PythonUtils instead of direct accessing Scala package

## What changes were proposed in this pull request?

This PR proposes to use add a helper in `PythonUtils` instead of direct accessing Scala package.

## How was this patch tested?

Jenkins tests.

Closes #22483 from HyukjinKwon/minor-refactoring.

Authored-by: hyukjinkwon <gurwls223@apache.org>
Signed-off-by: hyukjinkwon <gurwls223@apache.org>

Author: HyukjinKwon

core/src/main/scala/org/apache/spark/api/python/PythonUtils.scala

@@ -74,4 +74,8 @@ private[spark] object PythonUtils {
   def toScalaMap[K, V](jm: java.util.Map[K, V]): Map[K, V] = {
     jm.asScala.toMap
   }
+
+  def getEncryptionEnabled(sc: JavaSparkContext): Boolean = {
+    sc.conf.get(org.apache.spark.internal.config.IO_ENCRYPTION_ENABLED)
+  }
 }

python/pyspark/context.py

@@ -192,9 +192,7 @@ def _do_init(self, master, appName, sparkHome, pyFiles, environment, batchSize,
         # If encryption is enabled, we need to setup a server in the jvm to read broadcast
         # data via a socket.
         # scala's mangled names w/ $ in them require special treatment.
-        encryption_conf = self._jvm.org.apache.spark.internal.config.__getattr__("package$")\
-            .__getattr__("MODULE$").IO_ENCRYPTION_ENABLED()
-        self._encryption_enabled = self._jsc.sc().conf().get(encryption_conf)
+        self._encryption_enabled = self._jvm.PythonUtils.getEncryptionEnabled(self._jsc)
 
         self.pythonExec = os.environ.get("PYSPARK_PYTHON", 'python')
         self.pythonVer = "%d.%d" % sys.version_info[:2]