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/test/java/org/elasticsearch/xpack/security/audit/AuditTrailServiceTests.java
verify(licenseState).isAllowed(Security.AUDITING_FEATURE);
        if (isAuditingAllowed) {
            for (AuditTrail auditTrail : auditTrails) {
                verify(auditTrail).authenticationSuccess(requestId, authentication, restRequest);
            }
        } else {
            verifyNoMoreInteractions(auditTrails.toArray((Object[]) new AuditTrail[auditTrails.size()]));
        }
    }
    public void testAuthenticationSuccessTransport() throws Exception {
        Authentication authentication = AuthenticationTestHelper.builder()
            .user(new User("not-_username", "not-r1"))
            .realmRef(new RealmRef("_realm", "_type", "node", null))
            .runAs()
            .user(new User("_username", "r1"))
            .realmRef(new RealmRef("_look", "_type", "node", null))
            .build();
        final String requestId = randomAlphaOfLengthBetween(6, 12);
        service.get().authenticationSuccess(requestId, authentication, "_action", request);
        verify(licenseState).isAllowed(Security.AUDITING_FEATURE);
        if (isAuditingAllowed) {
            for (AuditTrail auditTrail : auditTrails) {
                verify(auditTrail).authenticationSuccess(requestId, authentication, "_action", request);
            }
        } else {
            verifyNoMoreInteractions(auditTrails.toArray((Object[]) new AuditTrail[auditTrails.size()]));
        }
    }
}