Welcome there,
The aiStarter emulator is about Android 6 I think, and the version does not support Firebase. Try to use AI Companion on an actual phone to test that out. If you do not have one, use a Genymotion emulator instead of the Google Android emulator.
Set up your Genymotion emulator here.
EDIT 2 MONTHS LATER: Actually, it is Android 2.2, which even does not support Firebase.