You can add a root certificate to Android, but if you're not a superuser (haven't "rooted" your phone, different usage) you can only add it as a "user" certificate, not a "system" certificate. After I believe Android 7 apps will by default not trust "user" certificates, so this would not help you, but since newer devices should include the LE root cert this just might be a viable solution. It's still not perfect. It's confusing and (probably by design) somewhat difficult for a lay user to do. And Android will give you a scary message every time it starts, saying your phone may be compromised.