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/logfile/LoggingAuditTrailTests.java
private static void restOrTransportOrigin(
        TransportRequest request,
        ThreadContext threadContext,
        MapBuilder<String, String> checkedFields
    ) {
        final InetSocketAddress restAddress = RemoteHostHeader.restRemoteAddress(threadContext);
        if (restAddress != null) {
            checkedFields.put(LoggingAuditTrail.ORIGIN_TYPE_FIELD_NAME, LoggingAuditTrail.REST_ORIGIN_FIELD_VALUE)
                .put(LoggingAuditTrail.ORIGIN_ADDRESS_FIELD_NAME, NetworkAddress.format(restAddress));
        } else {
            final InetSocketAddress address = request.remoteAddress();
            if (address != null) {
                checkedFields.put(LoggingAuditTrail.ORIGIN_TYPE_FIELD_NAME, LoggingAuditTrail.TRANSPORT_ORIGIN_FIELD_VALUE)
                    .put(LoggingAuditTrail.ORIGIN_ADDRESS_FIELD_NAME, NetworkAddress.format(address));
            }
        }
    }
    private static void authentication(Authentication authentication, MapBuilder<String, String> checkedFields) {
        checkedFields.put(LoggingAuditTrail.PRINCIPAL_FIELD_NAME, authentication.getUser().principal());
        checkedFields.put(LoggingAuditTrail.AUTHENTICATION_TYPE_FIELD_NAME, authentication.getAuthenticationType().toString());
        if (authentication.isApiKey()) {
            assert false == authentication.isRunAs();
            checkedFields.put(
                LoggingAuditTrail.API_KEY_ID_FIELD_NAME,
                (String) authentication.getMetadata().get(AuthenticationField.API_KEY_ID_KEY)
            );
            String apiKeyName = (String) authentication.getMetadata().get(AuthenticationField.API_KEY_NAME_KEY);
            if (apiKeyName != null) {
                checkedFields.put(LoggingAuditTrail.API_KEY_NAME_FIELD_NAME, apiKeyName);
            }