Remove Chromium-specific directories from zlib fuzzer includes

Make the include changes initially proposed in
https://android-review.git.corp.google.com/c/platform/external/zlib/+/1458722.
Android stores its zlib in its own project, which does not include the
`third_party` directory. Include zlib.h directly, assuming that its
folder is included in the include dirs. This is the first step towards
allowing Android to run zlib's fuzzers.

Bug: b/242299736
Change-Id: Ia98ab0ebcc8b4d5a4e4aa39706c80e26cd4d485e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4023343


Reviewed-by: Adenilson Cavalcanti <cavalcantii@chromium.org>
Auto-Submit: Leon Scroggins <scroggo@google.com>
Reviewed-by: Chris Blume <cblume@chromium.org>
Commit-Queue: Leon Scroggins <scroggo@google.com>
Reviewed-by: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1071867}
NOKEYCHECK=True
GitOrigin-RevId: 6206581fe3c40611c80dd80e8d9f766b3c5c82ae