OP, your title "Non smartphone wallet" and your question are in complete opposition since you are asking for Android type wallet, and any phone with that OS falls into the category of a smartphone.
Isn't this risky?
Of course, it's risky, so old models generally no longer have support from their manufacturers in the form of security patches issued by Google every month. And there is no doubt that such smartphones pose a security risk, not only because of the fact that they have an outdated OS, but also because of the inability to use new versions of applications.
I would not hesitate to use such a smartphone for ordinary internet surfing or something, but under no circumstances would I use it for crypto hot wallet.