Add RIL requests for Emergency Call domain selection HAL API changes.

Add the following:
- RIL_REQUEST_SET_EMERGENCY_MODE
- RIL_REQUEST_TRIGGER_EMERGENCY_NETWORK_SCAN
- RIL_REQUEST_CANCEL_EMERGENCY_NETWORK_SCAN
- RIL_REQUEST_EXIT_EMERGENCY_MODE

- RIL_UNSOL_EMERGENCY_NETWORK_SCAN_RESULT

Test: Build
Bug: 243344927
Change-Id: I62b8f26460858d1b608075466c4ad26114c69b8a