Update Skia/SkiaPaths expectations for some corpus tests

CL [1] reverts a previous CL [2] and fixed the issue that unwanted
black borders were rendered in some rectangular images/masks. This CL
updates the affected corpus tests accordingly.

[1] https://pdfium-review.googlesource.com/100930
[2] https://pdfium-review.googlesource.com/100174

Bug: pdfium:1818,pdfium:1896
Change-Id: I94a694f6e8534c7b551335c29c39eb5b10300a7a
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium_tests/+/100970
Reviewed-by: Lei Zhang <thestig@chromium.org>