Follow-up from "Stop liveness check returning incorrect data"

The following discussion from !17655 (merged) should be addressed:

• @engwan started a discussion: (+4 comments)

  Thanks @seanarnold! Looks good to me.

  My only concern would be that this may break external scripts that depend on this response body already? I'm not sure if we strictly follow SemVer and only make breaking changes in major versions.

  This seems like a pretty minor breaking change though.

  I'll let @dzaporozhets decide on that, I think he knows more about our policy.