Merge "Upgrade libxml2 to e1bcffea180d6cc0651757bb64284a763e0e2239" am: e89c501e7f

Original change: https://android-review.googlesource.com/c/platform/external/libxml2/+/1706766

Change-Id: I236eef9c75df112984e40409a504221ef9b7a82f