HelloStereo Sample is upside down when using vulkan

[GrantComm]

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Describe the bug
The hellostereo sample is upside down when running with vulkan.

To Reproduce
Steps to reproduce the behavior:
Build filament with multiview
Run the hellostereo sample with ./out/cmake-debug/samples/hellostereo -a vulkan

Expected behavior
When working properly, the two heads in the top left and right corners should be right side up and rotating.

Screenshots

Logs
N/A

Desktop (please complete the following information):

• OS: Linux
• GPU
• Backend: Vulkan

Smartphone (please complete the following information):
N/A

Additional context
N/A