Looks like Xcode isn't generating any UIDeviceRequiredCapabilities
for watchOS 1 extensions.
It used to have UIRequiredDeviceCapabilities = 'watch-companion'
but that *might* not be required anymore.
Commit 94e35a8570 on xamarin-macios/master
comes from those same assumptions.
Now regarding bug #41204:
User is getting error "ERROR ITMS-90563: "Missing UIRequiredDeviceCapabilities value"
when publish WatchKitCatalog sample.
(https://bugzilla.xamarin.com/show_bug.cgi?id=41204)
This might happen because we're still creating an empty array for the
UIDeviceRequiredCapabilities key.
In any case there's no need to create it.
Xcode doesn't see to add a UIRequiredDeviceCapabilities = 'watch-companion'
anymore for watchos apps/extensions, not even when setting the deployment
version to 2.0.
This makes watchOS 2 apps launch in the simulator again.
MSBuild compares what is in FileWrites with the Outputs of the target
and any file that exists in FileWrites but *doesn't* exist in Outputs
gets deleted with the assumption that it is no longer needed via the
IncrementalClean MSBuild target.
Since these tasks cannot know what the outputs will be until the task
is run, we cannot use FileWrites.