Update AGG, Skia & SkiaPaths expectations for 2 corpus tests

Corpus tests all_trigger_browsefordoc.pdf and all_trigger_newdoc.pdf
can be rendered across platforms with all renderers (AGG, Skia and
SkiaPaths). This CL updates the expectations for these tests so that
they can be enabled and pass.

Bug: pdfium:1798
Change-Id: Ib4c8b14d41faeca988d4cc8250af9bd10bf8617c
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium_tests/+/99290
Reviewed-by: Lei Zhang <thestig@chromium.org>