Checkstyle: Make Pojo method parameters final

Author: rozza

bson/src/test/unit/org/bson/codecs/pojo/entities/conventions/BsonIgnoreDuplicatePropertyMultipleTypes.java

@@ -39,12 +39,12 @@ public String getAltStringField() {
     }
 
     @BsonIgnore
-    public void setAltStringField(String altStringField) {
+    public void setAltStringField(final String altStringField) {
         this.altStringField = altStringField;
     }
 
     @BsonIgnore
-    public void setAltStringField(Integer i) {
+    public void setAltStringField(final Integer i) {
         this.altStringField = i.toString();
     }