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/transport/filter/IPFilterTests.java
Settings.EMPTY,
            new HashSet<>(
                Arrays.asList(
                    IPFilter.HTTP_FILTER_ALLOW_SETTING,
                    IPFilter.HTTP_FILTER_DENY_SETTING,
                    IPFilter.IP_FILTER_ENABLED_HTTP_SETTING,
                    IPFilter.IP_FILTER_ENABLED_SETTING,
                    IPFilter.TRANSPORT_FILTER_ALLOW_SETTING,
                    IPFilter.TRANSPORT_FILTER_DENY_SETTING,
                    IPFilter.PROFILE_FILTER_ALLOW_SETTING,
                    IPFilter.PROFILE_FILTER_DENY_SETTING
                )
            )
        );
        httpTransport = mock(HttpServerTransport.class);
        TransportAddress httpAddress = new TransportAddress(InetAddress.getLoopbackAddress(), 9200);
        when(httpTransport.boundAddress()).thenReturn(new BoundTransportAddress(new TransportAddress[] { httpAddress }, httpAddress));
        when(httpTransport.lifecycleState()).thenReturn(Lifecycle.State.STARTED);
        transport = mock(Transport.class);
        TransportAddress address = new TransportAddress(InetAddress.getLoopbackAddress(), 9300);
        when(transport.boundAddress()).thenReturn(new BoundTransportAddress(new TransportAddress[] { address }, address));
        when(transport.lifecycleState()).thenReturn(Lifecycle.State.STARTED);
        Map<String, BoundTransportAddress> profileBoundAddresses = Collections.singletonMap(
            "client",
            new BoundTransportAddress(new TransportAddress[] { new TransportAddress(InetAddress.getLoopbackAddress(), 9500) }, address)
        );
        when(transport.profileBoundAddresses()).thenReturn(profileBoundAddresses);
    }
    public void testThatIpV4AddressesCanBeProcessed() throws Exception {
        Settings settings = Settings.builder()