Improved Fast Deployment doesn't work with Application subclasses

Setting the `$(AndroidFastDeploymentType)` MSBuild property to `Assemblies:Dexes` enables enhanced fast deployment, which reduces the circumstances in which a .apk needs to be rebuilt:

https://developer.xamarin.com/releases/android/xamarin.android_7/xamarin.android_7.2/#Fast_Deployment

If the project contains an `Android.App.Application` subclass, the application will fail to start.


Reference: https://bugzilla.xamarin.com/show_bug.cgi?id=55050