[vulkan] fix -Wreorder-init-list

C++20 is stricter about member ordering in designated initializers than
C99.

Bug: 139945549
Test: mm
Change-Id: I8532a1b8d224605c91f2f5a046f548385243a7cf
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>