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
public static void lookupPatternLayout() throws Exception {
        final Properties properties = new Properties();
        try (InputStream configStream = LoggingAuditTrail.class.getClassLoader().getResourceAsStream("log4j2.properties")) {
            properties.load(configStream);
        }
        
        
        
        
        
        assertThat(properties.getProperty("logger.xpack_security_audit_logfile.name"), is(LoggingAuditTrail.class.getName()));
        assertThat(properties.getProperty("logger.xpack_security_audit_logfile.appenderRef.audit_rolling.ref"), is("audit_rolling"));
        assertThat(properties.getProperty("appender.audit_rolling.name"), is("audit_rolling"));
        assertThat(properties.getProperty("appender.audit_rolling.layout.type"), is("PatternLayout"));
        final String patternLayoutFormat = properties.getProperty("appender.audit_rolling.layout.pattern");
        assertThat(patternLayoutFormat, is(notNullValue()));
        patternLayout = PatternLayout.newBuilder().withPattern(patternLayoutFormat).withCharset(StandardCharsets.UTF_8).build();
        customAnonymousUsername = randomAlphaOfLength(8);
        reservedRealmEnabled = randomBoolean();
    }
    @AfterClass
    public static void releasePatternLayout() {
        patternLayout = null;
    }
    
    @Before
    public void init() throws Exception {
        includeRequestBody = randomBoolean();
        settings = Settings.builder()
            .put(LoggingAuditTrail.EMIT_HOST_ADDRESS_SETTING.getKey(), randomBoolean())