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
PRINCIPAL_ROLES_FIELD_NAME,
            new String[] { randomAlphaOfLengthBetween(1, 6) }
        );
        final String realm = randomAlphaOfLengthBetween(1, 6);
        
        final TransportRequest[] requests = new TransportRequest[] {
            new MockRequest(threadContext),
            new org.elasticsearch.action.MockIndicesRequest(IndicesOptions.strictExpandOpenAndForbidClosed(), new String[0]),
            new org.elasticsearch.action.MockIndicesRequest(IndicesOptions.strictExpandOpenAndForbidClosed(), (String[]) null) };
        final List<String> output = CapturingLogger.output(logger.getName(), Level.INFO);
        int logEntriesCount = 1;
        for (final TransportRequest request : requests) {
            auditTrail.anonymousAccessDenied("_req_id", "_action", request);
            assertThat(output.size(), is(logEntriesCount++));
            assertThat(output.get(logEntriesCount - 2), not(containsString("indices=")));
            auditTrail.authenticationFailed("_req_id", createAuthenticationToken(), "_action", request);
            assertThat(output.size(), is(logEntriesCount++));
            assertThat(output.get(logEntriesCount - 2), not(containsString("indices=")));
            auditTrail.authenticationFailed("_req_id", "_action", request);
            assertThat(output.size(), is(logEntriesCount++));
            assertThat(output.get(logEntriesCount - 2), not(containsString("indices=")));
            auditTrail.authenticationFailed("_req_id", realm, mockToken(), "_action", request);
            assertThat(output.size(), is(logEntriesCount++));
            assertThat(output.get(logEntriesCount - 2), not(containsString("indices=")));
            auditTrail.accessGranted(
                "_req_id",
                randomBoolean() ? createAuthentication() : createApiKeyAuthenticationAndMaybeWithRunAs(createAuthentication()),
                "_action",
                request,
                authorizationInfo