I am looking for a way to store AWS secrets (Cognito ID and others) to use in my tests. All of the ways I found included third party plugins, like vault from HachiCorp. I haven't found a solution that allows me to easily have them accessible for local testing. I use Github Secrets for my Github Actions. The tests are in commonTest module.
You can use BuildKonfig, since the latest release it allows adding directly values from the gradle file. You can add your values only for test builds using gradle flags.