Move SkiaGpuContext creation in SkiaVkRenderEngine to virtual function

Making GaneshVkRenderEngine / GraphiteVkRenderEngine handle this reduces
the need for higher-level branching.

Test: boots successfully with skiavkthreaded
Bug: b/293371537
Change-Id: I5685cb9dd7b0dc1ce3a2d538a729c255fbd6c52b
diff --git a/libs/renderengine/skia/SkiaVkRenderEngine.cpp b/libs/renderengine/skia/SkiaVkRenderEngine.cpp
index 473fa0a..3715859 100644
--- a/libs/renderengine/skia/SkiaVkRenderEngine.cpp
+++ b/libs/renderengine/skia/SkiaVkRenderEngine.cpp
@@ -112,12 +112,9 @@
     sSetupVulkanInterface();
 
     SkiaRenderEngine::Contexts contexts;
-    contexts.first = SkiaGpuContext::MakeVulkan_Ganesh(sVulkanInterface.getGaneshBackendContext(),
-                                                       mSkSLCacheMonitor);
+    contexts.first = createContext(sVulkanInterface);
     if (supportsProtectedContentImpl()) {
-        contexts.second = SkiaGpuContext::MakeVulkan_Ganesh(sProtectedContentVulkanInterface
-                                                                    .getGaneshBackendContext(),
-                                                            mSkSLCacheMonitor);
+        contexts.second = createContext(sProtectedContentVulkanInterface);
     }
 
     return contexts;