Generate copyright year in swagger template code

- exclude generated source code from checkstyle by default

Change-Id: I3f79183a8aae1f24d36558860555b5b0298cd8c3
diff --git a/tools/package/maven-plugin/src/main/java/org/onosproject/maven/OnosSwaggerMojo.java b/tools/package/maven-plugin/src/main/java/org/onosproject/maven/OnosSwaggerMojo.java
index fb0eab5..0d44913 100644
--- a/tools/package/maven-plugin/src/main/java/org/onosproject/maven/OnosSwaggerMojo.java
+++ b/tools/package/maven-plugin/src/main/java/org/onosproject/maven/OnosSwaggerMojo.java
@@ -41,6 +41,7 @@
 import java.io.FileWriter;
 import java.io.IOException;
 import java.io.PrintWriter;
+import java.time.Year;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
@@ -477,7 +478,8 @@
                 src = src.replace("${api.package}", apiPackage)
                         .replace("${web.context}", webContext)
                         .replace("${api.title}", apiTitle)
-                        .replace("${api.description}", apiTitle);
+                        .replace("${api.description}", apiTitle)
+                        .replace("${year}", Year.now().toString());
                 Files.write(src.getBytes(), reg);
             } catch (IOException e) {
                 getLog().warn("Unable to write " + reg);