This updates flutter to 3.24.1, the latest stable version, and also updates our flutter dependencies to latest.
It targets the latest android sdk, 34, which is required if we want to publish a new version to the Google Play store.
I also needed to make a few adjustments to handle deprecations. The biggest change is that I needed to wrap the main widget in MaterialApp to avoid problems with AdaptiveSwitch in iOS.
- Updated README with some maybe-helpful instructions for downgrading
flutter to a version that will build the project
- Added a step to create a missing directory to the Gradle build
(otherwise the build fails)
- Set `shrinkResources false` - otherwise you get an error that you
can't shrink resources unless you also enable minifying