It depends where. I used to do Android training in Malaysia. There's substantially more Android devs here, because colleges don't have the budget to do iOS training and many people can't afford a Macbook. iOS jobs would pay about 30% more for the same work or less.

So people would switch from Android to iOS because of the pay if they could.

At senior levels, Android tends to pay better because there's lots of really niche knowledge, especially around the differences between Xiaomi/Samsung/custom devices as well as how locale/currency is handled. I just wrote a 1000 character essay complaining about the differences, but it's besides the point.