Add static buffer support

src/gpu/vk/GrVkBuffer.h

Index: src/gpu/vk/GrVkBuffer.h
diff --git a/src/gpu/vk/GrVkBuffer.h b/src/gpu/vk/GrVkBuffer.h
index 0bfbecace101f039fac59f65b95332485c42789d..985b586336107f9ae57cea1ccf835b35ad60dbf1 100644
--- a/src/gpu/vk/GrVkBuffer.h
+++ b/src/gpu/vk/GrVkBuffer.h
@@ -79,7 +79,7 @@ protected:
     void vkUnmap(const GrVkGpu* gpu);
     // If the caller passes in a non null createdNewBuffer, this function will set the bool to true
     // if it creates a new VkBuffer to upload the data to.
-    bool vkUpdateData(const GrVkGpu* gpu, const void* src, size_t srcSizeInBytes,
+    bool vkUpdateData(GrVkGpu* gpu, const void* src, size_t srcSizeInBytes,
                       bool* createdNewBuffer = nullptr);
 
     void vkAbandon();