Add logic to notify phone of the emergency callback mode changes

This commit adds logic to notify phone of the emergency callback mode changes.
Logic added to call the following method:
  - Phone#startEmergencyCallbackMode(int, long)
  - Phone#restartEmergencyCallbackMode(int, long)
  - Phone#stopEmergencyCallbackMode(int, int)

Bug: 359064059
Test: atest EmergencyStateTrackerTest
Test: atest GsmCdmaCallTrackerTest, atest ImsPhoneCallTrackerTest
Flag: com.android.internal.telephony.flags.emergency_callback_mode_notification
Change-Id: Id3e595d5aa0d4e51b6ec8a91aa4fbc5a9c9188c8