Replace entries in additional-spring-configuration-metadata.json with code

[mhalbritter]

The file additional-spring-configuration-metadata.json in spring-boot-actuator-autoconfigure contains enabled properties for JmxProperties, PrometheusProperties and SimpleProperties. These entries are not necessary, as they can be generated from the configuration property classes. Remove the entries from the JSON and add fields to the classes. This makes it easier to keep the metadata and the code in sync.