BTA_GATTS_AddCharDescriptor() function

* Function BTA_GATTS_AddCharDescriptor * Description This function is called to add characteristic descriptor. When * it's done, a callback event BTA_GATTS_ADD_DESCR_EVT is called * to report the status and an ID number for this descriptor. * Parameters service_id: service ID to which this charatceristic descriptor is to * be added. * perm: descriptor access permission. * p_descr_uuid: descriptor UUID. * p_descr_params: descriptor value if it's read only descriptor. * Returns returns status.