Add @test to testInt8List and fix it

This makes sure it is run. This was caught by error-prone.

The test was also failing, so fix the copy-paste error in
PrimitiveFieldType that broke it.

Author: drigz

message_generation/src/main/java/org/ros/internal/message/field/PrimitiveFieldType.java

@@ -81,7 +81,7 @@ public Byte getDefaultValue() {
 
     @Override
     public Field newVariableList(String name, int size) {
-      return ChannelBufferField.newVariable(this, name, size);
+      return ByteArrayField.newVariable(this, name, size);
     }
 
     @Override

message_generation/src/test/java/org/ros/internal/message/MessageTest.java

@@ -114,6 +114,7 @@ public void testConstantString() {
     assertEquals("Hello, ROS! # comment", rawMessage.getString("data"));
   }
 
+  @Test
   public void testInt8List() {
     topicDefinitionResourceProvider.add("foo/foo", "int8[] data");
     RawMessage rawMessage = messageFactory.newFromType("foo/foo");