[automerge] Fix a bug when getting a gzip header extra field with inflate(). 2p: 1729242482 am: c362b4c096 am: 24ade94114 am: 51ad95bb4c

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/zlib/+/20545969

Change-Id: Icbbc0c2368c1836cae592c250b22614a6a5c4e91
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>