MutidexKeep file does not work for android espresso apk to declare classes required in the primary DEX file

Question

My test apk has multiple classes.dex . I am trying to get all the classes to appear in the main classes.dex using the multiDexKeepFile and also the multiDexKeepProguard property as mentioned in

https://developer.android.com/studio/build/multidex.html#keep. I am adding

    multiDexKeepFile file('multidex-config.txt')
    multiDexKeepProguard file('multidexKeepConfig.txt')

in the build.gradle under automation build types

android {
buildTypes {
    automation {
        multiDexKeepFile file('multidex-config.txt')
        ...
    }
}

}

Once I generate the test apk , I still dont see the classes listed in my multidex-config.txt and multidexKeepConfig.txt appear in the first classes.dex.

I am not sure if this is a limitation with espresso test apk, as the above link talks about adding it in the release build type