expo: create-manifest scripts in expo updates missing

🐛 Bug Report

Environment

Expo CLI 3.20.1 environment info: System: OS: macOS 10.15.4 Shell: 5.7.1 - /bin/zsh Binaries: Node: 13.0.0 - /usr/local/bin/node Yarn: 1.22.4 - /usr/local/bin/yarn npm: 6.12.0 - /usr/local/bin/npm Watchman: 4.9.0 - /usr/local/bin/watchman IDEs: Android Studio: 3.6 AI-192.7142.36.36.6392135 Xcode: 11.4.1/11E503a - /usr/bin/xcodebuild npmPackages: expo: ^37.0.8 => 37.0.8 react: ~16.9.0 => 16.9.0 react-dom: ~16.9.0 => 16.9.0 react-native: ~0.61.5 => 0.61.5 react-native-web: ~0.11.7 => 0.11.7 react-navigation: ^2.18.2 => 2.18.3 npmGlobalPackages: expo-cli: 3.20.1

Steps to Reproduce

expo eject npm install expo-updates open android studio -> build

Expected Behavior

build should work after following documentation of setting up expo updates for bare workflow

Actual Behavior

android studio returns build error “/node_modules/expo-assets/scripts/create-manifest-android.gradle’ as it does not exist”

following the guide to set up expo -updates. but so far its not working!. in your instructions you listed to add this line " …/node_modules/expo-updates/scripts/create-manifest-ios.sh " to the build_phases in xCode and " …/node_modules/expo-updates/scripts/create-manifest-android.gradle" in the build.gradle file in android, but i checked and none of these files exist, therefore the build fails. I tried to remove the line, the build works but the assets are not bundled correctly . please update your documentation or include steps to get these files. it is frustrating trying to debug this and trying to get a release build out

Reproducible Demo