Now we have a nice Setting infra, we can define in Setting class if a setting should be filtered or not.
So when we register a setting, setting filtering would be automatically done.
Instead of writing:
```java
Setting<String> KEY_SETTING = Setting.simpleString("cloud.aws.access_key", false, Setting.Scope.CLUSTER);
settingsModule.registerSetting(AwsEc2Service.KEY_SETTING, false);
settingsModule.registerSettingsFilterIfMissing(AwsEc2Service.KEY_SETTING.getKey());
```
We could simply write:
```java
Setting<String> KEY_SETTING = Setting.simpleString("cloud.aws.access_key", false, Setting.Scope.CLUSTER, true);
settingsModule.registerSettingsFilterIfMissing(AwsEc2Service.KEY_SETTING.getKey());
```
It also removes `settingsModule.registerSettingsFilterIfMissing` method.
The plan would be to remove as well `settingsModule.registerSettingsFilter` method but it still used with wildcards. For example in Azure Repository plugin:
```java
module.registerSettingsFilter(AzureStorageService.Storage.PREFIX + "*.account");
module.registerSettingsFilter(AzureStorageService.Storage.PREFIX + "*.key");
```
Closes#16598.
aabb124209