Create a new test for `RTL2f` spec

[maratal]

Current test for RTL2f doesn't test what the spec implies (and was removed):

A test should exist to ensure that resumed is always false when a channel first becomes ATTACHED, it is true when the channel is ATTACHED following a successful connection recovery, and is false when the channel is ATTACHED following a failed connection recovery

┆Issue is synchronized with this Jira Task by Unito

[jamienewcomb]

closing - we can reopen if we plan to proceed