Fix stall in Vk clear

src/gpu/vk/GrVkGpu.cpp

Index: src/gpu/vk/GrVkGpu.cpp
diff --git a/src/gpu/vk/GrVkGpu.cpp b/src/gpu/vk/GrVkGpu.cpp
index a208aed456405f8184f14cfc7eaed0e9c6dbda2b..a0e6aa554d26e1b05d16d583eb663d727937dde3 100644
--- a/src/gpu/vk/GrVkGpu.cpp
+++ b/src/gpu/vk/GrVkGpu.cpp
@@ -1041,6 +1041,8 @@ void GrVkGpu::onClear(GrRenderTarget* target, const SkIRect& rect, GrColor color
         }
         clearRect.rect.offset = { vkRect.fLeft, vkRect.fTop };
         clearRect.rect.extent = { (uint32_t)vkRect.width(), (uint32_t)vkRect.height() };
+        clearRect.baseArrayLayer = 0;
+        clearRect.layerCount = 1;
 
         const GrVkRenderPass* renderPass = vkRT->simpleRenderPass();
         SkASSERT(renderPass);