Update hwui_unit_tests to support running with Vulkan backend.

Added Macros for RENDERTHREAD_TESTS which run these tests using specific backends.
RENDERTHREAD_TESTS - Runs OpenGL, SkiaGL, and SkiaVulkan
RENDERTHREAD_SKIA_TESTS - Runs SkiaGL and SkiaVulkan
RENDERTHREAD_OPENGL_TESTS - Runs OpenGL

Test: manual running of hwui_unit_tests

Change-Id: Ia7420ee7a38803a15e2d58394d14b38cae8208d3
diff --git a/libs/hwui/tests/unit/RenderNodeTests.cpp b/libs/hwui/tests/unit/RenderNodeTests.cpp
index 331a6ac..ab8e4e1 100644
--- a/libs/hwui/tests/unit/RenderNodeTests.cpp
+++ b/libs/hwui/tests/unit/RenderNodeTests.cpp
@@ -137,10 +137,11 @@
 RENDERTHREAD_TEST(RenderNode, prepareTree_HwLayer_AVD_enqueueDamage) {
 
     VectorDrawable::Group* group = new VectorDrawable::Group();
-    VectorDrawableRoot* vectorDrawable = new VectorDrawableRoot(group);
+    sp<VectorDrawableRoot> vectorDrawable(new VectorDrawableRoot(group));
+
     auto rootNode = TestUtils::createNode(0, 0, 200, 400,
             [&](RenderProperties& props, Canvas& canvas) {
-        canvas.drawVectorDrawable(vectorDrawable);
+        canvas.drawVectorDrawable(vectorDrawable.get());
     });
     ContextFactory contextFactory;
     std::unique_ptr<CanvasContext> canvasContext(CanvasContext::create(
@@ -164,7 +165,5 @@
     EXPECT_FALSE(info.layerUpdateQueue->entries().empty());
     EXPECT_EQ(rootNode.get(), info.layerUpdateQueue->entries().at(0).renderNode);
     EXPECT_EQ(uirenderer::Rect(0, 0, 200, 400), info.layerUpdateQueue->entries().at(0).damage);
-
-    delete vectorDrawable;
     canvasContext->destroy(nullptr);
 }