Merge "Upgrade libxml2 to 7279d236364739a05657a8a614c15990eb08d0c6" am: 7cb4d979c3 am: 80288015e5 am: b7ae737b76

Original change: https://android-review.googlesource.com/c/platform/external/libxml2/+/1699085

Change-Id: I287f2d2f5af7cc8f4bd6b3cd533c8f2ad0874e31