build: pin javadoc copyright footer to avoid 1980 year

The maven-javadoc-plugin derives the footer copyright year from the build
timestamp. In a reproducible-build environment (SOURCE_DATE_EPOCH=0), that
clamps to 1980, so published -javadoc artifacts (e.g. 2.3.0) show
'Copyright (c) 1980' and drop the generation date. Set an explicit
year-less <bottom> so the footer no longer depends on the build clock,
keeping builds reproducible while rendering a correct notice.

Author: hsilan

pom.xml

@@ -171,6 +171,12 @@
                     <version>3.12.0</version>
                     <configuration>
                         <doclint>none</doclint>
+                        <!-- Fixed footer so the copyright year is not derived from the
+                             build timestamp. Without this, a reproducible-build
+                             environment (SOURCE_DATE_EPOCH=0) renders the footer year as
+                             1980. A year-less notice keeps builds reproducible and
+                             regression-proof. -->
+                        <bottom>Copyright &#169; Amazon.com, Inc. or its affiliates. All rights reserved.</bottom>
                     </configuration>
                 </plugin>
             </plugins>