Update corpus tests for correctly rendered push buttons

These tests all contain push buttons which were rendered lighter or had
extra layer of color. Correct them to the new expectations.

BUG=chromium:638626

Change-Id: I4470fcec9a6cb83c47d6e22adb7684a6e48c635d
Reviewed-on: https://pdfium-review.googlesource.com/3810
Reviewed-by: dsinclair <dsinclair@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
45 files changed