Implement various vulkan stencil clears and fix various stenciling bugs.

src/gpu/vk/GrVkRenderTarget.cpp

Index: src/gpu/vk/GrVkRenderTarget.cpp
diff --git a/src/gpu/vk/GrVkRenderTarget.cpp b/src/gpu/vk/GrVkRenderTarget.cpp
index 87f1f77e392fb3832cc30556349e8e1fa8e8dd1c..ee45aa30e87cf44fe4a918cca779f83ef3c94de8 100644
--- a/src/gpu/vk/GrVkRenderTarget.cpp
+++ b/src/gpu/vk/GrVkRenderTarget.cpp
@@ -196,7 +196,6 @@ GrVkRenderTarget::CreateNewRenderTarget(GrVkGpu* gpu,
     GrVkRenderTarget* rt = GrVkRenderTarget::Create(gpu, desc, lifeCycle, imageResource);
     // Create() will increment the refCount of the image resource if it succeeds
     imageResource->unref(gpu);
-
     return rt;
 }