[SPARK-17531] Don't initialize Hive Listeners for the Execution Client

## What changes were proposed in this pull request?

If a user provides listeners inside the Hive Conf, the configuration for these listeners are passed to the Hive Execution Client as well. This may cause issues for two reasons:
1. The Execution Client will actually generate garbage
2. The listener class needs to be both in the Spark Classpath and Hive Classpath

This PR empties the listener configurations in `HiveUtils.newTemporaryConfiguration` so that the execution client will not contain the listener confs, but the metadata client will.

## How was this patch tested?

Unit tests

Author: Burak Yavuz <brkyvz@gmail.com>

Closes #15086 from brkyvz/null-listeners.

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveUtils.scala

@@ -394,6 +394,13 @@ private[spark] object HiveUtils extends Logging {
     // hive.metastore.uris is not set.
     propMap.put(ConfVars.METASTOREURIS.varname, "")
 
+    // The execution client will generate garbage events, therefore the listeners that are generated
+    // for the execution clients are useless. In order to not output garbage, we don't generate
+    // these listeners.
+    propMap.put(ConfVars.METASTORE_PRE_EVENT_LISTENERS.varname, "")
+    propMap.put(ConfVars.METASTORE_EVENT_LISTENERS.varname, "")
+    propMap.put(ConfVars.METASTORE_END_FUNCTION_LISTENERS.varname, "")
+
     propMap.toMap
   }
 

sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveUtilsSuite.scala

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.spark.sql.hive
+
+import org.apache.hadoop.hive.conf.HiveConf.ConfVars
+
+import org.apache.spark.sql.hive.test.TestHiveSingleton
+import org.apache.spark.sql.test.SQLTestUtils
+import org.apache.spark.sql.QueryTest
+
+class HiveUtilsSuite extends QueryTest with SQLTestUtils with TestHiveSingleton {
+
+  test("newTemporaryConfiguration overwrites listener configurations") {
+    Seq(true, false).foreach { useInMemoryDerby =>
+      val conf = HiveUtils.newTemporaryConfiguration(useInMemoryDerby)
+      assert(conf(ConfVars.METASTORE_PRE_EVENT_LISTENERS.varname) === "")
+      assert(conf(ConfVars.METASTORE_EVENT_LISTENERS.varname) === "")
+      assert(conf(ConfVars.METASTORE_END_FUNCTION_LISTENERS.varname) === "")
+    }
+  }
+}