Update min Vulkan version to 1.0.8.0, and fix various bugs

tools/vulkan/VulkanTestContext.cpp

Index: tools/vulkan/VulkanTestContext.cpp
diff --git a/tools/vulkan/VulkanTestContext.cpp b/tools/vulkan/VulkanTestContext.cpp
index b940656357bb5c53dbc66218ae8f4b8ea6c88e28..8273e4cd8799cfa7c8f0de8acdf69b6250eacbf7 100644
--- a/tools/vulkan/VulkanTestContext.cpp
+++ b/tools/vulkan/VulkanTestContext.cpp
@@ -240,14 +240,14 @@ bool VulkanTestContext::createSwapchain(uint32_t width, uint32_t height)
                                                                    nullptr));
     }
 
-    GrVkFormatToPixelConfig(swapchainCreateInfo.imageFormat, &fPixelConfig);
-
-    this->createBuffers();
+    this->createBuffers(swapchainCreateInfo.imageFormat);
 
     return true;
 }
 
-void VulkanTestContext::createBuffers() {
+void VulkanTestContext::createBuffers(VkFormat format) {
+    GrVkFormatToPixelConfig(format, &fPixelConfig);
+
     GR_VK_CALL_ERRCHECK(fBackendContext->fInterface, GetSwapchainImagesKHR(fBackendContext->fDevice,
                                                                            fSwapchain,
                                                                            &fImageCount,
@@ -271,6 +271,7 @@ void VulkanTestContext::createBuffers() {
         info.fAlloc = nullptr;
         info.fImageLayout = VK_IMAGE_LAYOUT_COLOR_ATTACHMENT_OPTIMAL;
         info.fImageTiling = VK_IMAGE_TILING_OPTIMAL;
+        info.fFormat = format;
         desc.fWidth = fWidth;
         desc.fHeight = fHeight;
         desc.fConfig = fPixelConfig;