Merge "Add a libz_stable variant" am: 0a3c0efda6 am: e039a563c8 am: d2dca3d813

Original change: https://android-review.googlesource.com/c/platform/external/zlib/+/1548534

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I89a65a674b5030d956645742ede736efe4897cbf