Make copy texture test more extensive

By doing the copy multiple times, we exercise both paths where the
destination is already initialized and when it's not.

This adds tests for all combinations of formats and flags.

Bug: angleproject:2958
Change-Id: I56afb44496acd1b4d5a8527f4dbee29afbac9c81
Reviewed-on: https://chromium-review.googlesource.com/c/1398643
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/renderer/vulkan/RenderbufferVk.cpp b/src/libANGLE/renderer/vulkan/RenderbufferVk.cpp
index c6e8907..f92b34f 100644
--- a/src/libANGLE/renderer/vulkan/RenderbufferVk.cpp
+++ b/src/libANGLE/renderer/vulkan/RenderbufferVk.cpp
@@ -24,7 +24,7 @@
 }  // anonymous namespace
 
 RenderbufferVk::RenderbufferVk(const gl::RenderbufferState &state)
-    : RenderbufferImpl(state), mRenderTarget(&mImage, &mImageView, 0)
+    : RenderbufferImpl(state), mRenderTarget(&mImage, &mImageView, 0, nullptr)
 {}
 
 RenderbufferVk::~RenderbufferVk() {}