AXIS2-5904 Add Javadoc to PolicySubject.getVersion()

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: robertlazarski

modules/kernel/src/org/apache/axis2/description/PolicySubject.java

@@ -120,6 +120,13 @@ public void setLastUpdatedTime(Date lastUpdatedTime) {
         this.version = VERSION_COUNTER.incrementAndGet();
     }
 
+    /**
+     * Returns the current version of the policy set, represented by a
+     * monotonically increasing number. This version number changes every
+     * time a policy is attached, detached, updated, or cleared.
+     *
+     * @return the current policy version
+     */
     public long getVersion() {
         return version;
     }