add-to-app via CocoaPods cannot find flutter_assets on iOS 14 #63552
Description
Run https://github.com/flutter/samples/tree/master/add_to_app/ios_fullscreen via the CocoaPods integration path.
Fails to launch the Flutter screen on iOS 14 / Xcode 12
Failed to find assets path for "Frameworks/App.framework/flutter_assets"
[VERBOSE-2:engine.cc(148)] Engine run configuration was invalid.
[VERBOSE-2:shell.cc(487)] Could not launch engine with configuration.
flutter: Observatory listening on http://127.0.0.1:63033/hwmX53Eqeq0=/
Interestingly, once I launch it once via iOS 13 / Xcode 11, then go back to iOS 14 / Xcode 12, it works.
cc @jmagman