Otherwise, the siblings that do not needs_system_composite could be incorrectly occluded by the child that needs_system_composite. More specifically, if one child acquires a vulkan surface (needs_system_composite), all the siblings need to acquire vulkan surfaces as well.

To see the bug, enable PerformanceOverlayLayer (which currently does not needs_system_composite) in Fuchsia with a Flutter app that has a PhysicalShapeLayer (which needs_system_composite) as a child of the root_layer_. The PerformanceOverlayLayer is completely occluded.