Enable RenderEngine blur testing on more devices.

Test: atest renderengine_test
Bug: 176903027
Change-Id: I85e3a561548506bd9cab1a6c8f7e15c47fbff960
diff --git a/libs/renderengine/skia/SkiaGLRenderEngine.h b/libs/renderengine/skia/SkiaGLRenderEngine.h
index 8ef7359..5779ae6 100644
--- a/libs/renderengine/skia/SkiaGLRenderEngine.h
+++ b/libs/renderengine/skia/SkiaGLRenderEngine.h
@@ -61,6 +61,7 @@
     bool isProtected() const override { return mInProtectedContext; }
     bool supportsProtectedContent() const override;
     bool useProtectedContext(bool useProtectedContext) override;
+    bool supportsBackgroundBlur() override { return mBlurFilter != nullptr; }
 
 protected:
     void dump(std::string& result) override;