fix: zIndex prop edge case
fix: zIndex prop edge case

This commit ensures the view "layer" exists before trying to set "zIndex".

ptmt/react-native-macos,ptmt/react-native-macos,ptmt/react-native-macos,ptmt/react-native-macos,ptmt/react-native-macos,ptmt/react-native-macos,ptmt/react-native-macos,ptmt/react-native-macos