DO NOT MERGE Fix potential DoS caused by delivering signal to BT process

Bug: 28885210
Change-Id: I63866d894bfca47464d6e42e3fb0357c4f94d360

 Conflicts:
	btif/co/bta_hh_co.c
	btif/src/btif_core.c
Merge conflict resolution of ag/1161415 (referencing ag/1164670)
- Directly into mnc-mr2-release

static bool send_app_scn(rfc_slot_t *slot) {
 if(slot->scn_notified == true) {
 return true;
 }
  slot->scn_notified = true;
 return sock_send_all(slot->fd, (const uint8_t*)&slot->scn, sizeof(slot->scn)) == sizeof(slot->scn);
}

static bool send_app_scn(rfc_slot_t *slot) {
 if(slot->scn_notified == true) {
 return true;
 }
  slot->scn_notified = true;
 return sock_send_all(slot->fd, (const uint8_t*)&slot->scn, sizeof(slot->scn)) == sizeof(slot->scn);
}
