I received an email from Google that we need to start supporting 64-bit CPUs in our Android apps by August 1, 2019. In their documentation, it states that there should be a lib/
Go into your Project settings / Build / Android Build / Advanced and enable arm64-v8a as one of your supported ABIs.
Project settings / Build / Android Build / Advanced
arm64-v8a
And then do a fresh build (or a new archive if you are using that feature of VS).
Note: Make sure you do this for your Release configuration