Floss: introduce |CreateBondWithRetry| to |Stack::Message|

In some contexts, the media policy (|bluetooth_media|) may need to
invoke |CreateBond|, and retry that multiple times when |PairingIsBusy|.

In this CL, we bridge the two APIs and expose a new type of
|Stack::Message| that will attempt to |CreateBond| and retry with the
specified parameters until |PairingIsBusy| is not.

Bug: 317682584
Test: m Bluetooth
Change-Id: I7b77b8fbc7bd4a4376bfc85ca5bc05f280d3875d