I need to generate an unsigned, release APK (where someone else will then sign it and release it to the store- with the someone else handling the keys and e
I had to do the same thing (because app signing is handled elsewhere) and I simply rebuilt the project.
To generate an unsigned release apk, select a release version in the Build Variants menu.
Note: You may get a red cross in your app configuration on the top menu, ignore it.
Rebuild your project application Build > Rebuild Project.
You will find your app-release-unsigned.apk in:
Note: If you need to create other versions, save the generated apk because subsequent rebuilds will overwrite the current apk(...don't be like me).