samples: bluetooth: fix periodic_sync_rsp sample connection

Was broken after BT_LE_ADV_OPT_USE_NAME and
BT_LE_ADV_OPT_FORCE_NAME_IN_AD were deprecated.

The periodic_adv_rsp sample
looks for the string "PAwR sync sample" and connects based on that.

So, the periodic_sync_rsp sample needs to advertise this string.

Signed-off-by: Olivier Lesage <olivier.lesage@nordicsemi.no>