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
new ConfigurableClusterPrivilege[] {
                new ConfigurableClusterPrivileges.WriteProfileDataPrivileges(new LinkedHashSet<>(Arrays.asList("", "\""))),
                new ConfigurableClusterPrivileges.ManageApplicationPrivileges(Set.of("\"")) },
            new String[] { "\"[a]/" },
            Map.of(),
            Map.of()
        );
        String keyName = randomAlphaOfLength(4);
        TimeValue expiration = randomFrom(new TimeValue(randomNonNegativeLong(), randomFrom(TimeUnit.values())), null);
        List<RoleDescriptor> allTestRoleDescriptors = List.of(
            nullRoleDescriptor,
            roleDescriptor1,
            roleDescriptor2,
            roleDescriptor3,
            roleDescriptor4,
            roleDescriptor5
        );
        List<RoleDescriptor> keyRoleDescriptors = randomSubsetOf(allTestRoleDescriptors);
        StringBuilder roleDescriptorsStringBuilder = new StringBuilder().append("\"role_descriptors\":[");
        keyRoleDescriptors.forEach(roleDescriptor -> {
            roleDescriptorsStringBuilder.append(auditedRolesMap.get(roleDescriptor.getName()));
            roleDescriptorsStringBuilder.append(',');
        });
        if (false == keyRoleDescriptors.isEmpty()) {
            
            roleDescriptorsStringBuilder.deleteCharAt(roleDescriptorsStringBuilder.length() - 1);
        }
        roleDescriptorsStringBuilder.append("]");
        final String requestId = randomRequestId();
        final String[] expectedRoles = randomArray(0, 4, String[]::new, () -> randomBoolean() ? null : randomAlphaOfLengthBetween(1, 4));