Disable Vulkan backend when running hwui_unit_tests.

The Vulkan backend fails to run on devices without vulkan drivers.
Until we can stub out the vulkan drivers for those devices we find
an acceptable solution.

Test: hwui_unit_tests on device w/out vulkan
Bug: 37422708
Change-Id: I3d7c21882053459f25ca1eb5648cdf5dfd4c333e
diff --git a/libs/hwui/tests/common/TestUtils.h b/libs/hwui/tests/common/TestUtils.h
index 0c7bb60..dd45786 100644
--- a/libs/hwui/tests/common/TestUtils.h
+++ b/libs/hwui/tests/common/TestUtils.h
@@ -88,7 +88,8 @@
     }; \
     INNER_PIPELINE_RENDERTHREAD_TEST(test_case_name, test_name, OpenGL); \
     INNER_PIPELINE_RENDERTHREAD_TEST(test_case_name, test_name, SkiaGL); \
-    INNER_PIPELINE_RENDERTHREAD_TEST(test_case_name, test_name, SkiaVulkan); \
+    /* Temporarily disabling Vulkan until we can figure out a way to stub out the driver */ \
+    /* INNER_PIPELINE_RENDERTHREAD_TEST(test_case_name, test_name, SkiaVulkan); */ \
     void test_case_name##_##test_name##_RenderThreadTest::doTheThing(renderthread::RenderThread& renderThread)
 
 /**
@@ -111,7 +112,8 @@
         static void doTheThing(renderthread::RenderThread& renderThread); \
     }; \
     INNER_PIPELINE_RENDERTHREAD_TEST(test_case_name, test_name, SkiaGL); \
-    INNER_PIPELINE_RENDERTHREAD_TEST(test_case_name, test_name, SkiaVulkan); \
+    /* Temporarily disabling Vulkan until we can figure out a way to stub out the driver */ \
+    /* INNER_PIPELINE_RENDERTHREAD_TEST(test_case_name, test_name, SkiaVulkan); */ \
     void test_case_name##_##test_name##_RenderThreadTest::doTheThing(renderthread::RenderThread& renderThread)
 
 /**