[chore]: Add deprecation message for hyphenated fields and cleanup `self.log` in cc_rh_subscription.py

[mostafaCamel]

As @blackboxsw explained in a related PR, the convention is to use snake_case field names. For already-existing fields with hyphens in cc_rh_subscription.py, we should add a deprecation message as is the case here

[mostafaCamel]

We should also cleanup the self.log calls in this file . See #6347 (comment) for reference

[mostafaCamel]

#6470