[Vulkan][TCC] Fix quantized shaders (#89456)
Summary: Fix rounding issue in quantized shaders
Test Plan:
On Mac
```
cd ~/fbsource
buck1 run -c pt.vulkan_full_precision=1 //xplat/caffe2:pt_vulkan_quantized_api_test_binAppleMac\#macosx-arm64
```
On Android
```
cd ~/fbsource
buck1 build -c ndk.custom_libcxx=false -c pt.enable_qpl=0 -c pt.vulkan_full_precision=1 //xplat/caffe2:pt_vulkan_quantized_api_test_binAndroid\#android-arm64 --show-output
adb push buck-out/gen/xplat/caffe2/pt_vulkan_quantized_api_test_binAndroid\#android-arm64 /data/local/tmp/vulkan_quantized_api_test
adb shell "/data/local/tmp/vulkan_quantized_api_test"
```
Reviewed By: salilsdesai
Differential Revision: D41047095
Pull Request resolved: https://github.com/pytorch/pytorch/pull/89456
Approved by: https://github.com/kirklandsign, https://github.com/digantdesai
