React Native installRelease Task 'installRelease' not found in root project 'timeReportTool'. Some candidates are: 'uninstallRelease'
You have to create a signing key and reference it in your project, as described here: https://facebook.github.io/react-native/docs/signed-apk-android
It's crazy that no one answered this for over a year. There's no way around this issue if you publish a React-Native app to the Play Store.