Convert 6 image files to Git LFS

Projects/OpenXRTest/Resources/GameSDK.ico,Projects/OpenXRTest/Resources/LegacyLogoLauncher.bmp,Projects/OpenXRTest/Resources/Platform/Mac/Images.xcassets/TestDPAppIcon.appiconset/icon_128.png,Projects/OpenXRTest/Resources/Platform/Mac/Images.xcassets/TestDPAppIcon.appiconset/icon_128_2x.png,Projects/OpenXRTest/Resources/Platform/Mac/Images.xcassets/TestDPAppIcon.appiconset/icon_16.png,Projects/OpenXRTest/Resources/Platform/Mac/Images.xcassets/TestDPAppIcon.appiconset/icon_16_2x.png: convert to Git LFS

Signed-off-by: amzn-phist <[email protected]>