Let LayerDrawable choose the best scaling filter for readback.

The check used in Readback.cpp did not take the transformation
matrix into account for judging whether the copy was scaling.

libs/hwui/pipeline/skia/LayerDrawable.cpp already incorporates
the logic to detect non-scaling copy, so we can just let it
check the condition. This version regards 90-degree rotation
without size change as non-scaling and disables filters.

Bug: 151126720
Bug: 150839078
Test: atest android.view.cts.PixelCopyTest
Change-Id: I69e987e6a2e48299c5e579f8c218c42a724dc606

libs/hwui/Readback.cpp

@@ -146,12 +146,11 @@ CopyResult Readback::copyImageInto(const sk_sp<SkImage>& image, Matrix4& texTran
     }
 
     Layer layer(mRenderThread.renderState(), nullptr, 255, SkBlendMode::kSrc);
-    bool disableFilter = MathUtils::areEqual(skiaSrcRect.width(), skiaDestRect.width()) &&
-                         MathUtils::areEqual(skiaSrcRect.height(), skiaDestRect.height());
-    layer.setForceFilter(!disableFilter);
     layer.setSize(displayedWidth, displayedHeight);
     texTransform.copyTo(layer.getTexTransform());
     layer.setImage(image);
+    // Scaling filter is not explicitly set here, because it is done inside copyLayerInfo
+    // after checking the necessity based on the src/dest rect size and the transformation.
     if (copyLayerInto(&layer, &skiaSrcRect, &skiaDestRect, bitmap)) {
         copyResult = CopyResult::Success;
     }