[automerger] DO NOT MERGE Add null check to EmergencyCallbackModeExitDialog activity. am: 78fab1f98d am: 06c169f3db am: 04676b86b4 skipped: c20ea0938b am: a91ef0b14b

Change-Id: Ie68260478d2bcd0e77933cbd67bfd61b7e8bd1af