Some types of audit event samples from [our documentation](https://www.elastic.co/guide/en/elasticsearch/reference/7.17/audit-event-types.html) include the port number in "origin.address", like **access_denied**:
```json
{"type":"audit", "timestamp":"2020-12-30T22:30:06,949+0200", "node.id":
"0RMNyghkQYCc_gVd1G6tZQ", "event.type":"transport", "event.action":
"access_denied", "authentication.type":"REALM", "user.name":"user1",
"user.realm":"default_native", "user.roles":["test_role"], "origin.type":
"rest", "origin.address":"[::1]:52434", "request.id":"yKOgWn2CRQCKYgZRz3phJw",
"action":"indices:admin/auto_create", "request.name":"CreateIndexRequest",
"indices":["<index-{now/d+1d}>"]}
```
but other types like **connection_denied** from this issue does not include the port:

```json
{"type":"audit", "timestamp":"2020-12-30T21:47:31,526+0200", "node.id":
"0RMNyghkQYCc_gVd1G6tZQ", "event.type":"ip_filter", "event.action":
"connection_denied", "origin.type":"rest", "origin.address":"10.10.0.20",
"transport.profile":".http", "rule":"deny 10.10.0.0/16"}
```

I think we should be consistent here and always include the port number in the "origin.address" field.
x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/audit/AuditTrailService.java
private static final Logger logger = LogManager.getLogger(AuditTrailService.class);
    private static final AuditTrail NOOP_AUDIT_TRAIL = new NoopAuditTrail();
    private final CompositeAuditTrail compositeAuditTrail;
    private final XPackLicenseState licenseState;
    private final Duration minLogPeriod = Duration.ofMinutes(30);
    protected AtomicReference<Instant> nextLogInstantAtomic = new AtomicReference<>(Instant.EPOCH);
    public AuditTrailService(List<AuditTrail> auditTrails, XPackLicenseState licenseState) {
        this.compositeAuditTrail = new CompositeAuditTrail(Collections.unmodifiableList(auditTrails));
        this.licenseState = licenseState;
    }
    public AuditTrail get() {
        if (compositeAuditTrail.isEmpty() == false) {
            if (Security.AUDITING_FEATURE.check(licenseState)) {
                return compositeAuditTrail;
            } else {
                maybeLogAuditingDisabled();
                return NOOP_AUDIT_TRAIL;
            }
        } else {
            return NOOP_AUDIT_TRAIL;
        }
    }
    
    
    public List<AuditTrail> getAuditTrails() {
        return compositeAuditTrail.auditTrails;