Rachel,
Think you'll have to pack commercial baby cereal then. That would be easier. But if you're going Australia, may not be able to bring cereal in. Anyway, there's a much wider range of baby cereals in Australia.
As for fruits, think you'll have to look out for soft fruits like banana, papaya...that would be easy to mash with fork to feed your baby...and no need to cook the fruits first.
Airlines, from what I hear from my airline frens, they do prepare if you let them know beforehand...but it'll be jar food...and stage 1 jar food. Coz it's like, they want to play safe, so give every baby under 1 year, stage 1 jar food.