Merge "Prevent integer overflow in function doProlog" into sc-dev am: d4d1050506 am: 48916e7c7a

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/expat/+/18723665

Change-Id: Id363ef7d4338600f66614e2e734da5e4599bf7df
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>