I'm not sure why anyone signed up to make Android phones. I can only assume it was panic about how far ahead the iPhone was when it was introduced. Microsoft and Intel made all the profits in the PC industry, the manufacturers fought over table scraps. The survivors like Dell quickly moved into enterprise services where they could make actual money.
The cell phone suckers signed up for the same thing in mobile: Let Google and the carriers make all the money while they duke it out gladiator-style to eek out a meager profit. In that situation you're left without the R&D budget to compete with the likes of Apple (who takes most of the profit in cell phones) or Samsung (who has a massive conglomerate including chip fabs, a battery business, and a display business!).
So the tl;dr is that Nokia making Android phones would have been, at best, a shadow of its former self. It was institutionally incapable of making that transition because it wanted to protect its former business. They also believed their carrier relationships would save them (aka the Carrier is the real customer for phones, not the end-user... end-users will take what the carrier offers and like it.) Nokia was also incapable of creating their own platform. The number of surviving companies who have successful done that can be counted with your fingers and all of them are based on the US west coast. It takes a software-is-king culture that neither Nokia nor Blackberry ever had. The only way Blackberry or Nokia survive is to immediately pivot the day the iPhone is announced, open huge software engineering offices in the Bay Area, and start developing their own platforms ASAP. Act as if you're going out of business immediately.
There is also a cautionary tale for startups: By the time you realize your competitor is going to eat your lunch it may be too late to do anything about it. You can't wait until you are losing 20% of your customers to react because it will take you 3-12 months to turn the ship and catch up, then at least as long again to mature features, inform customers, and hit purchasing windows. That can be up to two years you've been focused on catching up while your competitor was free to keep innovating. By the time you get it all sorted out you'll be losing 80-90% of your customers, only now the market is bigger and network effects are even stronger so you'll have to work twice as hard to get back to where you were.