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/logfile/LoggingAuditTrail.java
} else {
                    throw new IllegalStateException(
                        "Unknown message class type ["
                            + msg.getClass().getSimpleName()
                            + "] for the \"security change\" action ["
                            + action
                            + "]"
                    );
                }
            } catch (IOException e) {
                throw new ElasticsearchSecurityException("Unexpected error while serializing event data", e);
            }
        }
    }
    @Override
    public void explicitIndexAccessEvent(
        String requestId,
        AuditLevel eventType,
        Authentication authentication,
        String action,
        String index,
        String requestName,
        InetSocketAddress remoteAddress,
        AuthorizationInfo authorizationInfo
    ) {
        assert eventType == ACCESS_DENIED || eventType == AuditLevel.ACCESS_GRANTED || eventType == SYSTEM_ACCESS_GRANTED;
        final String[] indices = index == null ? null : new String[] { index };
        final User user = authentication.getUser();
        if (User.isInternal(user) && eventType == ACCESS_GRANTED) {
            eventType = SYSTEM_ACCESS_GRANTED;