[SPARK-15134][EXAMPLE] Indent SparkSession builder patterns and update binary_classification_metrics_example.py

## What changes were proposed in this pull request?

This issue addresses the comments in SPARK-15031 and also fix java-linter errors.
- Use multiline format in SparkSession builder patterns.
- Update `binary_classification_metrics_example.py` to use `SparkSession`.
- Fix Java Linter errors (in SPARK-13745, SPARK-15031, and so far)

## How was this patch tested?

After passing the Jenkins tests and run `dev/lint-java` manually.

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #12911 from dongjoon-hyun/SPARK-15134.

1 files changed, 0 insertions, 2 deletions

diff --git a/sql/hive-thriftserver/src/main/java/org/apache/hive/service/cli/session/SessionManager.java b/sql/hive-thriftserver/src/main/java/org/apache/hive/service/cli/session/SessionManager.java
index 0457b3781e..de066dd406 100644
--- a/sql/hive-thriftserver/src/main/java/org/apache/hive/service/cli/session/SessionManager.java
+++ b/sql/hive-thriftserver/src/main/java/org/apache/hive/service/cli/session/SessionManager.java
@@ -22,7 +22,6 @@ import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Date;
-import java.util.List;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.Future;
@@ -35,7 +34,6 @@ import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.hive.conf.HiveConf;
 import org.apache.hadoop.hive.conf.HiveConf.ConfVars;
-import org.apache.hadoop.hive.ql.hooks.HookUtils;
 import org.apache.hive.service.CompositeService;
 import org.apache.hive.service.cli.HiveSQLException;
 import org.apache.hive.service.cli.SessionHandle;