Fix a bug when getting a gzip header extra field with inflate(). am:...

Fix a bug when getting a gzip header extra field with inflate(). am: 1c4806af am: 9166f7db am: 2cf9f01b

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/zlib/+/20545926



Change-Id: I6f2942c2c138a1dad25cf95714a552322c738dda
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>