### Description

**Background**
As part of https://github.com/elastic/kibana/issues/104986 we will be adding the ability for Elastic Agents to send agent monitoring data to a remote Elasticsearch cluster. In order to achieve this, we will need a service token for the remote cluster which fleet server will use. 

This service account will need less permissions than the `elastic/fleet-server` as integration data will not be sent to remote clusters yet.

**Service Account Details**

Name: `elastic/fleet-server-remote`

Permissions:
-  for indices `logs-*`, `metrics-*` privileges "write", "create_index", "auto_configure"

x-pack/plugin/security/src/test/java/org/elasticsearch/xpack/security/authc/service/ServiceAccountServiceTests.java
new MockLogAppender.SeenEventExpectation(
                    "invalid magic byte again",
                    ServiceAccountToken.class.getName(),
                    Level.TRACE,
                    "service account token expects the 4 leading bytes"
                )
            );
            assertNull(
                ServiceAccountService.tryParseToken(new SecureString("AQEAAWVsYXN0aWMvZmxlZXQvdG9rZW4xOnN1cGVyc2VjcmV0".toCharArray()))
            );
            appender.assertAllExpectationsMatched();
            
            appender.addExpectation(
                new MockLogAppender.SeenEventExpectation(
                    "no colon again",
                    ServiceAccountToken.class.getName(),
                    Level.TRACE,
                    "failed to extract qualified service token name and secret, missing ':'"
                )
            );
            assertNull(
                ServiceAccountService.tryParseToken(new SecureString("AAEAAWVsYXN0aWMvZmxlZXQvdG9rZW4xX3N1cGVyc2VjcmV0".toCharArray()))
            );
            appender.assertAllExpectationsMatched();
            
            appender.addExpectation(
                new MockLogAppender.SeenEventExpectation(
                    "invalid delimiter for qualified name again",
                    ServiceAccountToken.class.getName(),
                    Level.TRACE,