Merge "zlib: changes so external/angle can reuse this copy of zlib." am: 4d02aae0 am: bfa589a9

Original change: https://android-review.googlesource.com/c/platform/external/zlib/+/2359720



Change-Id: I27a9fc165e34bf28d910c9a117859e9d9d8d07d3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>