It does not reproduce locally. I found this error in the logs which looks like a possible cause.
```
[2022-07-30T01:22:31,499][ERROR][o.e.r.s.FileSettingsService] [[elasticsearch[file-settings-watcher]]] Error processing operator settings json file
  1> java.lang.IllegalStateException: Error processing state change request for file_settings, errors: org.elasticsearch.xcontent.XContentParseException: [1:0] [reserved_state_chunk] Expected START_OBJECT but was: null
  1> 	at org.elasticsearch.xcontent.ObjectParser.throwExpectedStartObject(ObjectParser.java:330)
  1> 	at org.elasticsearch.xcontent.ObjectParser.parse(ObjectParser.java:275)
  1> 	at org.elasticsearch.xcontent.ConstructingObjectParser.parse(ConstructingObjectParser.java:166)
  1> 	at org.elasticsearch.xcontent.ConstructingObjectParser.apply(ConstructingObjectParser.java:158)
  1> 	at org.elasticsearch.reservedstate.service.ReservedClusterStateService.process(ReservedClusterStateService.java:103)
  1> 	at org.elasticsearch.reservedstate.service.FileSettingsService.processFileSettings(FileSettingsService.java:308)
  1> 	at org.elasticsearch.reservedstate.service.FileSettingsService.lambda$startWatcher$3(FileSettingsService.java:245)
  1> 	at java.base/java.lang.Thread.run(Thread.java:833)

  1> 	at org.elasticsearch.reservedstate.service.ReservedClusterStateService.process(ReservedClusterStateService.java:109) ~[main/:?]
  1> 	at org.elasticsearch.reservedstate.service.FileSettingsService.processFileSettings(FileSettingsService.java:308) ~[main/:?]
  1> 	at org.elasticsearch.reservedstate.service.FileSettingsService.lambda$startWatcher$3(FileSettingsService.java:245) ~[main/:?]
  1> 	at java.lang.Thread.run(Thread.java:833) ~[?:?]
  1> Caused by: org.elasticsearch.xcontent.XContentParseException: [1:0] [reserved_state_chunk] Expected START_OBJECT but was: null
  1> 	at org.elasticsearch.xcontent.ObjectParser.throwExpectedStartObject(ObjectParser.java:330) ~[elasticsearch-x-content-8.5.0-SNAPSHOT.jar:8.5.0-SNAPSHOT]
  1> 	at org.elasticsearch.xcontent.ObjectParser.parse(ObjectParser.java:275) ~[elasticsearch-x-content-8.5.0-SNAPSHOT.jar:8.5.0-SNAPSHOT]
  1> 	at org.elasticsearch.xcontent.ConstructingObjectParser.parse(ConstructingObjectParser.java:166) ~[elasticsearch-x-content-8.5.0-SNAPSHOT.jar:8.5.0-SNAPSHOT]
  1> 	at org.elasticsearch.xcontent.ConstructingObjectParser.apply(ConstructingObjectParser.java:158) ~[elasticsearch-x-content-8.5.0-SNAPSHOT.jar:8.5.0-SNAPSHOT]
  1> 	at org.elasticsearch.reservedstate.service.ReservedClusterStateService.process(ReservedClusterStateService.java:103) ~[main/:?]
  1> 	... 3 more
  1> [2022-07-30T01:22:31,502][INFO ][o.e.r.s.FileSettingsService] [[elasticsearch[file-settings-watcher]]] processing path [/mnt/secret/elastic+elasticsearch+main+periodic+ear/server/build/testrun/internalClusterTest/temp/org.elasticsearch.reservedstate.service.FileSettingsServiceIT_129CA1A8D872CBA3-001/tempDir-003/config/operator/settings.json] for [file_settings]
```


**Build scan:**
https://gradle-enterprise.elastic.co/s/pijicvldxziw4/tests/:server:internalClusterTest/org.elasticsearch.reservedstate.service.FileSettingsServiceIT/testSettingsApplied

**Reproduction line:**
`./gradlew ':server:internalClusterTest' --tests "org.elasticsearch.reservedstate.service.FileSettingsServiceIT.testSettingsApplied" -Dtests.seed=129CA1A8D872CBA3 -Dtests.locale=sr-BA -Dtests.timezone=Asia/Kamchatka -Druntime.java=17`

**Applicable branches:**
main

**Reproduces locally?:**
No

**Failure history:**
https://gradle-enterprise.elastic.co/scans/tests?tests.container=org.elasticsearch.reservedstate.service.FileSettingsServiceIT&tests.test=testSettingsApplied

**Failure excerpt:**
```
java.lang.Exception: Test abandoned because suite timeout was reached.

  at __randomizedtesting.SeedInfo.seed([129CA1A8D872CBA3]:0)

```
server/src/internalClusterTest/java/org/elasticsearch/reservedstate/service/FileSettingsServiceIT.java
"indices.recovery.max_bytes_per_sec": "50mb"
                 }
             }
        }""";
    private static String testErrorJSON = """
        {
             "metadata": {
                 "version": "%s",
                 "compatibility": "8.4.0"
             },
             "state": {
                 "not_cluster_settings": {
                     "search.allow_expensive_queries": "false"
                 }
             }
        }""";
    private void assertMasterNode(Client client, String node) {
        assertThat(
            client.admin().cluster().prepareState().execute().actionGet().getState().nodes().getMasterNode().getName(),
            equalTo(node)
        );
    }
    private void writeJSONFile(String node, String json) throws Exception {
        long version = versionCounter.incrementAndGet();
        FileSettingsService fileSettingsService = internalCluster().getInstance(FileSettingsService.class, node);
        Files.createDirectories(fileSettingsService.operatorSettingsDir());
        Files.write(fileSettingsService.operatorSettingsFile(), Strings.format(json, version).getBytes(StandardCharsets.UTF_8));
    }
    private CountDownLatch setupClusterStateListener(String node) {
        ClusterService clusterService = internalCluster().clusterService(node);