(chores) camel-csv: test code cleanups

- use static
- modernize code
diff --git a/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/CsvDataFormatCustomRecordConverterTest.java b/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/CsvDataFormatCustomRecordConverterTest.java
index ec75973..97fffb7 100644
--- a/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/CsvDataFormatCustomRecordConverterTest.java
+++ b/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/CsvDataFormatCustomRecordConverterTest.java
@@ -17,8 +17,6 @@
 package org.apache.camel.dataformat.csv;
 
 import java.util.List;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
 
 import org.apache.camel.Message;
 import org.apache.camel.component.mock.MockEndpoint;
@@ -51,7 +49,7 @@
     }
 
     private String getData() {
-        return Stream.of("A1", "B1", "C1").collect(Collectors.joining(";"));
+        return String.join(";", "A1", "B1", "C1");
     }
 
     @Override
diff --git a/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/CsvMarshalTest.java b/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/CsvMarshalTest.java
index d599467..0e61069 100644
--- a/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/CsvMarshalTest.java
+++ b/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/CsvMarshalTest.java
@@ -53,8 +53,8 @@
         output.expectedMessageCount(1);
 
         template.sendBody("direct:default", Arrays.<List> asList(
-                Arrays.asList("1"),
-                Arrays.asList("one")));
+                List.of("1"),
+                List.of("one")));
         output.assertIsSatisfied();
 
         String[] actuals = readOutputLines(0);
diff --git a/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/CsvUnmarshalStreamTest.java b/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/CsvUnmarshalStreamTest.java
index 76a35cc..5dc617d 100644
--- a/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/CsvUnmarshalStreamTest.java
+++ b/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/CsvUnmarshalStreamTest.java
@@ -84,7 +84,7 @@
         }
     }
 
-    class MyFileInputStream extends FileInputStream {
+    static class MyFileInputStream extends FileInputStream {
 
         MyFileInputStream(File file) throws FileNotFoundException {
             super(file);
diff --git a/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/TestUtils.java b/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/TestUtils.java
index 29f7d7d..8f47386 100644
--- a/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/TestUtils.java
+++ b/components/camel-csv/src/test/java/org/apache/camel/dataformat/csv/TestUtils.java
@@ -24,7 +24,7 @@
  */
 final class TestUtils {
 
-    protected static final String LS = System.lineSeparator();
+    static final String LS = System.lineSeparator();
 
     private TestUtils() {
         // Prevent instantiation