Allow SkiaVkRenderEngine to not be compiled

A device will use RenderEngine with either SkiaVk or SkiaGL, but never
both at the same time.  Given that the choice is controlled by a
build-time value in the device's "device.mk" file, to save space, we
should allow the RenderEngine back-ends to be optionally built.  For
now, we'll only do this for SkiaVkRenderEngine.

Test: Compile
Bug: 259323498
Change-Id: Id547feaee7e8aeb4e46759d3d7c9c5dbe18f5211
diff --git a/libs/renderengine/tests/RenderEngineTest.cpp b/libs/renderengine/tests/RenderEngineTest.cpp
index f3f2da8..7db95a7 100644
--- a/libs/renderengine/tests/RenderEngineTest.cpp
+++ b/libs/renderengine/tests/RenderEngineTest.cpp
@@ -112,6 +112,7 @@
     virtual bool useColorManagement() const = 0;
 };
 
+#ifdef RE_SKIAVK
 class SkiaVkRenderEngineFactory : public RenderEngineFactory {
 public:
     std::string name() override { return "SkiaVkRenderEngineFactory"; }
@@ -152,6 +153,8 @@
 public:
     bool useColorManagement() const override { return true; }
 };
+#endif // RE_SKIAVK
+
 class SkiaGLESRenderEngineFactory : public RenderEngineFactory {
 public:
     std::string name() override { return "SkiaGLRenderEngineFactory"; }
@@ -1557,11 +1560,17 @@
     expectBufferColor(Rect(kGreyLevels, 1), generator, 2);
 }
 
+#ifdef RE_SKIAVK
 INSTANTIATE_TEST_SUITE_P(PerRenderEngineType, RenderEngineTest,
                          testing::Values(std::make_shared<SkiaGLESRenderEngineFactory>(),
                                          std::make_shared<SkiaGLESCMRenderEngineFactory>(),
                                          std::make_shared<SkiaVkRenderEngineFactory>(),
                                          std::make_shared<SkiaVkCMRenderEngineFactory>()));
+#else  // RE_SKIAVK
+INSTANTIATE_TEST_SUITE_P(PerRenderEngineType, RenderEngineTest,
+                         testing::Values(std::make_shared<SkiaGLESRenderEngineFactory>(),
+                                         std::make_shared<SkiaGLESCMRenderEngineFactory>()));
+#endif // RE_SKIAVK
 
 TEST_P(RenderEngineTest, drawLayers_noLayersToDraw) {
     if (!GetParam()->typeSupported()) {