Add SCBM control to EmergencyStateTracker

After successfully sending an emergency SMS in the 5G SA TC of a carrier
that supports emergency callback mode, the TC failed due to the process
of the modem changing the current network(LTE) to NR due to
exitEmergencyMode. So, in this case, instead of calling
exitEmergencyMode, EmergencyStateTracker need to set the emergency mode
(MODE_EMERGENCY_CALLBACK) to the modem so that the modem can maintain
the current network(LTE).
This change applies the SCBM related logic to EmergencyStateTracker.
SCBM will be separately managed from ECBM, and when both ECBM and SCBM
are terminated, EmergencyStateTracker calls exitEmergencyMode on the
modem.

The followings are added when emergency callback mode supports:
 - Enter SCBM when emergency SMS is successfully sent.
 - Set MODE_EMERGENCY_CALLBACK on the modem when SCBM enters.
 - Exit SCBM when its timer is expired and send exitEmergencyMode to
   modem.
 - While in SCBM, if emergency call is started, then exit SCBM.
 - Whlie in SCBM, if emergency SMS is successfully sent or emergency SMS
   is received, then re-initiate SCBM timer.
 - While in SCBM, if sending emergency SMS is failed, then keep the SCBM
   timer.

Bug: 314849793
Bug: 300026427
Test: atest SmsDispatchersControllerTest, EmergencyStateTrackerTest
Test: manual (While in ECBM, SCBM entered and after both are expired,
exit emergency mode)
Test: manual (While in SCBM, emergency call started and exit SCBM, ECBM
entered)
Test: manual (Enter SCBM and exit emergency mode when it's expired)
Test: equipment test (SMS: 5G SA E911 2.2/2.5, Call: 5G SA E911 2.1)

Change-Id: I715a983dc26299d02afd60eb6d0fbcbfbae3d53e