Feature flags that are disabled by default cannot have a version field to FCV gate the feature.

Errors found while compiling IDL
storage_parameters.idl: (121, 8): ID0071: The 'version' attribute is not allowed for feature flag that defaults to false

This is problematic for the all feature flags multi-version variants as some of these feature flags don't exist in earlier binaries, but it is possible to enable them regardless due to the lack of FCV gating. Running in a configuration where only a subset of mongod's have a feature flag enabled will result in different behaviour across the cluster.