For Android 4.x you also need a fairly old version of Firefox. (They had breaking changes in the APK file at some point between 4-5).
I am not so sure these older builds of Firefox provide the certificates either.
To be fair, this is why this central certificates architecture is not great. I am very thankful that SSH doesn't use them in this way (it optionally can, but that is rare).
But at the same time I can't even be bothered to rant about phone manufacturers not supporting their devices correctly because... phones bore me too much to even type about them.
Biting the hand that feeds IT
