when I build an app with minimum information, It took 4.5mb size to build. I never found any app size less then it.
Either I put any information or not, at least it took 4.5mb. Why this is happened? Where We see 1.5mb-3mb is enough to build an app with complete data.
Maybe you can decompile the apk and make some changes, however, it is not recommended, you may break things. I never done it before, but I will surely have a look on it someday.