A new leak has appeared in Flutter 1.22.0-12.0.pre which wasn't present in 1.22.0-9.0.pre

A sample app that reproduces this:
Add2AppTest-1.22.0-12.0.pre-dev.zip

[✓] Flutter (Channel dev, 1.22.0-9.0.pre, on Mac OS X 10.15.6 19G2021, locale en-US)
• Flutter version 1.22.0-9.0.pre at /Users/danny.valente/Library/flutter/1.22.0-9.0.pre-dev
• Framework revision 7a43175 (3 weeks ago), 2020-08-28 23:18:04 -0400
• Engine revision 07e2520
• Dart version 2.10.0 (build 2.10.0-73.0.dev)

[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
• Android SDK at /Users/danny.valente/Library/Android/sdk
• Platform android-29, build-tools 29.0.2
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6222593)
• All Android licenses accepted.