You would be naive to believe that Android/iOS are secure in this respect. Pretty much every government in the world has a "need" to surveil their population, and have "insisted" upon this capability.
You're saying a State Government can request Google installs a 3rd party app on 1 million phones? If that's true then I'm genuinely astonished. And more so that it wasn't headline news at the time.
Or maybe there's more to this than currently is apparent.
Yes. That's what happened. (I'm not sure if the 1E6 phones claim is accurate, but it was a non-trivial chunk of people near MA).