Automatic merge from submit-queue
storage error: precondition failure should return invalid object error
In introducing the preconditions by @caesarxuchao , if check preconditions failed, it returns resource version conflict error. This is the wrong error to return, and instead it should return invalid object error. We need to separate these two types of errors.
See the implementation in etcd3 [https://github.com/kubernetes/kubernetes/blob/master/pkg/storage/etcd3/store.go#L467].
Also renaming "ErrCodeResourceVersionConflicts" to "ErrCodeVersionConflicts" for simpler reading.
1c72ba6810