How to deal with the .so file while publishing the app on the Play store?

I created release version of app that has java and cpp code in AS3.5.1 with its default gradle. After uploading the app I am facing issues of uploading zip file of native code as per the Google instructions. ( My file structure is not a matching with the file structure described on Google page - https://developer.android.com/studio/build/shrink-code#native-crash-support, I dont have folder named Universal and then after uploading the obj folder in zip form Google simply notifies that these files are not valid -path: app\build\intermediates\cmake\release\obj).
I am getting the error as
The native debug symbols contain an invalid directory obj. Only Android ABIs are supported. May be I am not able to understand ABIs (Application Binary Interfaces).

I had the same issue when uploading my object files to Google Play. Turns out the issue was that when decompressed the zip file hierarchy was not what Google Play's processor was expecting. You need to make sure that the directories for the supported architectures are all at the root of the zip file. Also you need to make sure there are no other hidden system files that might end up in the zip file (e.g. .DS_Store if doing this on Mac).
On my Mac: Navigate into the required obj directory (app/build/intermediates/cmake/release/obj for me) and run

zip -r symbols.zip x86* arm*

This will include the 32-bit and 64-bit x86 and arm architectures, which is all I need at time of writing. Then upload the symbols.zip file and it should work.