[SPARK-14011][CORE][SQL] Enable `LineLength` Java checkstyle rule

## What changes were proposed in this pull request?

[Spark Coding Style Guide](https://cwiki.apache.org/confluence/display/SPARK/Spark+Code+Style+Guide) has 100-character limit on lines, but it's disabled for Java since 11/09/15. This PR enables **LineLength** checkstyle again. To help that, this also introduces **RedundantImport** and **RedundantModifier**, too. The following is the diff on `checkstyle.xml`.

```xml
-        <!-- TODO: 11/09/15 disabled - the lengths are currently > 100 in many places -->
-        <!--
         <module name="LineLength">
             <property name="max" value="100"/>
             <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>
         </module>
-        -->
         <module name="NoLineWrap"/>
         <module name="EmptyBlock">
             <property name="option" value="TEXT"/>
 -167,5 +164,7
         </module>
         <module name="CommentsIndentation"/>
         <module name="UnusedImports"/>
+        <module name="RedundantImport"/>
+        <module name="RedundantModifier"/>
```

## How was this patch tested?

Currently, `lint-java` is disabled in Jenkins. It needs a manual test.
After passing the Jenkins tests, `dev/lint-java` should passes locally.

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #11831 from dongjoon-hyun/SPARK-14011.

2 files changed, 9 insertions, 7 deletions

diff --git a/sql/core/src/test/java/test/org/apache/spark/sql/JavaApplySchemaSuite.java b/sql/core/src/test/java/test/org/apache/spark/sql/JavaApplySchemaSuite.java
index ae9c8cc1ba..189cc3972c 100644
--- a/sql/core/src/test/java/test/org/apache/spark/sql/JavaApplySchemaSuite.java
+++ b/sql/core/src/test/java/test/org/apache/spark/sql/JavaApplySchemaSuite.java
@@ -145,12 +145,13 @@ public class JavaApplySchemaSuite implements Serializable {
 
     Dataset<Row> df = sqlContext.createDataFrame(rowRDD, schema);
     df.registerTempTable("people");
-    List<String> actual = sqlContext.sql("SELECT * FROM people").toJavaRDD().map(new Function<Row, String>() {
-      @Override
-      public String call(Row row) {
-        return row.getString(0) + "_" + row.get(1);
-      }
-    }).collect();
+    List<String> actual = sqlContext.sql("SELECT * FROM people").toJavaRDD()
+      .map(new Function<Row, String>() {
+        @Override
+        public String call(Row row) {
+          return row.getString(0) + "_" + row.get(1);
+        }
+      }).collect();
 
     List<String> expected = new ArrayList<>(2);
     expected.add("Michael_29");
diff --git a/sql/core/src/test/java/test/org/apache/spark/sql/JavaDataFrameSuite.java b/sql/core/src/test/java/test/org/apache/spark/sql/JavaDataFrameSuite.java
index f3c5a86e20..cf764c645f 100644
--- a/sql/core/src/test/java/test/org/apache/spark/sql/JavaDataFrameSuite.java
+++ b/sql/core/src/test/java/test/org/apache/spark/sql/JavaDataFrameSuite.java
@@ -220,7 +220,8 @@ public class JavaDataFrameSuite {
     StructType schema1 = StructType$.MODULE$.apply(fields1);
     Assert.assertEquals(0, schema1.fieldIndex("id"));
 
-    List<StructField> fields2 = Arrays.asList(new StructField("id", DataTypes.StringType, true, Metadata.empty()));
+    List<StructField> fields2 =
+        Arrays.asList(new StructField("id", DataTypes.StringType, true, Metadata.empty()));
     StructType schema2 = StructType$.MODULE$.apply(fields2);
     Assert.assertEquals(0, schema2.fieldIndex("id"));
   }