An internal checker should never be in the unspecified state.
CREATING
The checker is being created, provisioned, and configured. A checker in this state can be returned by `ListInternalCheckers` or `GetInternalChecker`, as well as by examining the `long running Operation
RUNNING
The checker is running and available for use. A checker in this state can be returned by `ListInternalCheckers` or `GetInternalChecker` as well as by examining the `long running Operation