Plumbing through GPU context priority from SF to RE

Test: Run the code. Check logcat.
      atest librenderengine_test
Bug: 168740533
Change-Id: I6e34c4064dfd75ac96b86e0af587a208fc93d975
diff --git a/libs/renderengine/threaded/RenderEngineThreaded.h b/libs/renderengine/threaded/RenderEngineThreaded.h
index cdfbd04..8b1e2de 100644
--- a/libs/renderengine/threaded/RenderEngineThreaded.h
+++ b/libs/renderengine/threaded/RenderEngineThreaded.h
@@ -63,6 +63,7 @@
                         base::unique_fd&& bufferFence, base::unique_fd* drawFence) override;
 
     void cleanFramebufferCache() override;
+    int getContextPriority() override;
 
 private:
     void threadMain(CreateInstanceFactory factory);