GAP: Set service_id before calling gap_release_ccb

Calling gap_release_ccb with a service_id == 0, which in turn
calls BTM_SecClrService with an ID of 0.

From the documentation for BTM_SecClrService:

  Service ID - Id of the service to remove. '0' removes all
               service records (except SDP).

Test: BLE connection and characteristic read
Change-Id: Icf309807f02e1faa273cf9bad9c09d9221a8bbfd