tests: Bluetooth: reproduce gatt settings bug

Reproduce #54470.

- client connects
- client writes to CF & CCC
- client bonds
- server reboots

After this, we would expect to have the CCC and CF values be correctly
restored from settings but they are not.

Additionally add the same test with BT_PRIVACY=y, which shows that the
feature is broken with that config (fixed in a subsequent commit).

Signed-off-by: Jonathan Rico <jonathan.rico@nordicsemi.no>