How can I get rid of unnecessary code in .apk file?

Question

I have an empty project (no classes whatsoever, no activities), only a dependency to com.google.android.material:material:1.3.0 for the code to compile (there is a style defined which uses this).

I enabled shrinking option, yet, after generating the signes APK, there is a classes.dex file in the apk with a shitload of code, even though the app has no code. Why and how to I get rid of those, to make sure the apk contains only what is needed, no extra bloatware? Thank you.

This is the expanded apk:

Answer 1

For code shrinking please turn on Proguard and you have the option to customized Proguard rules as you need.

   buildTypes {
    release {
        shrinkResources true
        minifyEnabled true
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
    debug {
    }
}

Answer 2

TRY 1

Open .jar file (appodeal.jar) and remove all .dex files.

TRY 2

Use the built-in inspection Java | Declaration redundancy | Unused declaration.

To run it on whole project go to Analyze -> Run inspection by name..., type Unused declaration and select desired scope. Then carefully check output and mark some classes as entry points if needed.

Select Unused declaration node in list and perform Safe delete action on all unused declarations at once.