Fix a bug when getting a gzip header extra field with inflate(). am: 1c4806afd7 am: 9166f7db98 am: 2cf9f01bff am: 8a773bf157 am: 6c697389df am: c5732312c6

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

Change-Id: I7a73fd50e2f9d098880c06fc90955977cbf30f78
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>